Objective: Increased mechanical stress and contractility characterizes normal left ventricular (LV) subendocardium (Endo) but whether Endo mitochondrial respiratory chain complex activities is reduced as compared to subepicardium (Epi) and whether pressure overload-induced LV hypertrophy (LVH) might modulate transmural gradients through increased reactive oxygen species (ROS) production is unknown. Methods: LVH ... More
Overexpression of nicastrin increases Abeta production.
Gamma-secretase cleavage is the final proteolytic step that releases the amyloid beta-peptide (Abeta) from the amyloid beta-protein precursor (APP). Significant evidence indicates that the presenilins (PS) are catalytic components of a high molecular weight gamma-secretase complex. The glycoprotein nicastrin was recently identified as a functional unit of this complex based ... More
Association of excitatory amino acid transporters, especially EAAT2, with cholesterol-rich lipid raft microdomains: importance for excitatory amino acid transporter localization and function.
AuthorsButchbach ME, Tian G, Guo H, Lin CL
JournalJ Biol Chem
PubMed ID15187084
In the present study, we investigated the role of membrane cholesterol in the function of glutamate transporters. Depletion of membrane cholesterol by methyl-beta-cyclodextrin resulted in reduced Na(+)-dependent glutamate uptake in primary cortical cultures. Glial glutamate transporter EAAT2-mediated uptake was more sensitive to this effect. Cell surface biotinylation and immunostaining experiments ... More
The characterization of mitochondrial permeability transition in clonal pancreatic beta-cells. Multiple modes and regulation.
Mitochondrial permeability transition (MPT), which contributes substantially to the regulation of normal mitochondrial metabolism, also plays a crucial role in the initiation of cell death. It is known that MPT is regulated in a tissue-specific manner. The importance of MPT in the pancreatic beta-cell is heightened by the fact that ... More
Obligate multivalent recognition of cell surface tomoregulin following selection from a multivalent phage antibody library.
AuthorsHeitner T, Satozawa N, McLean K, Vogel D, Cobb RR, Liu B, Mahmoudi M, Finster S, Larsen B, Zhu Y, Zhou H, Müller-Tiemann B, Monteclaro F, Zhao XY, Light DR
JournalJ Biomol Screen
PubMed ID17092910
'A therapeutic antibody candidate (AT-19) isolated using multivalent phage display binds native tomoregulin (TR) as a mul-timer not as a monomer. This report raises the importance of screening and selecting phage antibodies on native antigen and reemphasizes the possibility that potentially valuable antibodies are discarded when a monomeric phage display ... More
Reactive oxygen species production via NADPH oxidase mediates TGF-beta-induced cytoskeletal alterations in endothelial cells.
AuthorsHu T, Ramachandrarao SP, Siva S, Valancius C, Zhu Y, Mahadev K, Toh I, Goldstein BJ, Woolkalis M, Sharma K
JournalAm J Physiol Renal Physiol
PubMed ID16159901
'Cytoskeletal alterations in endothelial cells have been linked to nitric oxide generation and cell-cell interactions. Transforming growth factor (TGF)-beta has been described to affect cytoskeletal rearrangement in numerous cell types; however, the underlying pathway is unclear. In the present study, we found that human umbilical vein endothelial cells (HUVEC) have ... More
N-glycans are direct determinants of CFTR folding and stability in secretory and endocytic membrane traffic.
'N-glycosylation, a common cotranslational modification, is thought to be critical for plasma membrane expression of glycoproteins by enhancing protein folding, trafficking, and stability through targeting them to the ER folding cycles via lectin-like chaperones. In this study, we show that N-glycans, specifically core glycans, enhance the productive folding and conformational ... More
Olfactory horizontal basal cells demonstrate a conserved multipotent progenitor phenotype.
AuthorsCarter LA, MacDonald JL, Roskams AJ
JournalJ Neurosci
PubMed ID15215289
'Stem cells of adult regenerative organs share a common goal but few established conserved mechanisms. Within the neural stem cell niche of the mouse olfactory epithelium, we identified a combination of extracellular matrix (ECM) receptors that regulate adhesion and mitosis in non-neural stem cells [intercellular adhesion molecule-1 (ICAM-1), beta1, beta4, ... More
Lipid rafts in the maintenance of synapses, dendritic spines, and surface AMPA receptor stability.
AuthorsHering H, Lin CC, Sheng M
JournalJ Neurosci
PubMed ID12716933
'Cholesterol/sphingolipid microdomains (lipid rafts) in the membrane are involved in protein trafficking, formation of signaling complexes, and regulation of actin cytoskeleton. Here, we show that lipid rafts exist abundantly in dendrites of cultured hippocampal neurons, in which they are associated with several postsynaptic proteins including surface AMPA receptors. Depletion of ... More
The antimicrobial activity of marinocine, synthesized by Marinomonas mediterranea, is due to hydrogen peroxide generated by its lysine oxidase activity.
AuthorsLucas-Elío P, Gómez D, Solano F, Sanchez-Amat A
JournalJ Bacteriol
PubMed ID16547036
'Marinocine is a broad-spectrum antibacterial protein synthesized by the melanogenic marine bacterium Marinomonas mediterranea. This work describes the basis for the antibacterial activity of marinocine and the identification of the gene coding for this protein. The antibacterial activity is inhibited under anaerobic conditions and by the presence of catalase under ... More
Involvement of the acid sphingomyelinase pathway in uva-induced apoptosis.
AuthorsZhang Y, Mattjus P, Schmid PC, Dong Z, Zhong S, Ma WY, Brown RE, Bode AM, Schmid HH, Dong Z
JournalJ Biol Chem
PubMed ID11278294
'The sphingomyelin-ceramide pathway is an evolutionarily conserved ubiquitous signal transduction system that regulates many cell functions including apoptosis. Sphingomyelin (SM) is hydrolyzed to ceramide by different sphingomyelinases. Ceramide serves as a second messenger in mediating cellular effects of cytokines and stress. In this study, we find that acid sphingomyelinase (SMase) ... More
Oxidative alpha-ketoglutarate dehydrogenase inhibition via subtle elevations in monoamine oxidase B levels results in loss of spare respiratory capacity: implications for Parkinson's disease.
AuthorsKumar MJ, Nicholls DG, Andersen JK
JournalJ Biol Chem
PubMed ID12963742
'Age-related increases in brain monoamine oxidase B (MAO-B) and its ability to produce reactive oxygen species as a by-product of catalysis could contribute to neurodegeneration associated with Parkinson''s disease. This may be via increased oxidative stress and/or mitochondrial dysfunction either on its own or through its interaction with endogenous or ... More
Gialpha3 protein-coupled dopamine D3 receptor-mediated inhibition of renal NHE3 activity in SHR proximal tubular cells is a PLC-PKC-mediated event.
AuthorsPedrosa R, Gomes P, Hopfer U, Jose PA, Soares-da-Silva P
JournalAm J Physiol Renal Physiol
PubMed ID15265766
'This study evaluated the transduction pathway associated with type 3 Na(+)/H(+) exchanger (NHE3) activity-induced inhibition during dopamine D(3) receptor activation in immortalized renal proximal tubular epithelial cells from the spontaneously hypertensive rat. The dopamine D(3) receptor agonist 7-OH-DPAT decreased NHE3 activity, which was prevented by the D(2)-like receptor antagonist S-sulpiride, ... More
Regulation of collagen deposition and lysyl oxidase by tumor necrosis factor-alpha in osteoblasts.
AuthorsPischon N, Darbois LM, Palamakumbura AH, Kessler E, Trackman PC
JournalJ Biol Chem
PubMed ID15138266
'Tumor necrosis factor-alpha (TNF-alpha) inhibits osteoblast function in vitro by inhibiting collagen deposition. Studies generally support that TNF-alpha does not inhibit collagen biosynthesis by osteoblasts but that collagen deposition is in some way diminished. The study investigated TNF-alpha regulation of biosynthetic enzymes and proteins crucial for posttranslational extracellular collagen maturation ... More
Real-time monitoring of histamine released from rat basophilic leukemia (RBL-2H3) cells with a histamine microsensor using recombinant histamine oxidase.
AuthorsIwaki S, Ogasawara M, Kurita R, Niwa O, Tanizawa K, Ohashi Y, Maeyama K
JournalAnal Biochem
PubMed ID12009701
'To detect low levels of histamine, we developed a histamine microsensor using recombinant histamine oxidase. Histamine oxidase with a histidine tag was readily purified using a histidine affinity column. The enzyme showed higher catalytic activity on histamine than diamines (e.g., putrescine and cadaverine) or N(tau)-methylhistamine. The sensor had three carbon ... More
Measurement of enzyme kinetics using a continuous-flow microfluidic system.
AuthorsSeong GH, Heo J, Crooks RM
JournalAnal Chem
PubMed ID12964765
'This paper describes a microanalytical method for determining enzyme kinetics using a continuous-flow microfluidic system. The analysis is carried out by immobilizing the enzyme on microbeads, packing the microbeads into a chip-based microreactor (volume approximately 1.0 nL), and flowing the substrate over the packed bed. Data were analyzed using the ... More
Amyloidogenic processing of the Alzheimer beta-amyloid precursor protein depends on lipid rafts.
AuthorsEhehalt R, Keller P, Haass C, Thiele C, Simons K
JournalJ Cell Biol
PubMed ID12515826
'Formation of senile plaques containing the beta-amyloid peptide (A beta) derived from the amyloid precursor protein (APP) is an invariant feature of Alzheimer''s disease (AD). APP is cleaved either by beta-secretase or by alpha-secretase to initiate amyloidogenic (release of A beta) or nonamyloidogenic processing of APP, respectively. A key to ... More
Continuous translocation of Rac2 and the NADPH oxidase component p67(phox) during phagocytosis.
Authorsvan Bruggen R, Anthony E, Fernandez-Borja M, Roos D
JournalJ Biol Chem
PubMed ID14623873
'In this study, the translocation of the NADPH oxidase components p67(phox) and Rac2 was studied during phagocytosis in living cells. For this purpose, green fluorescent protein (GFP)-tagged versions of these proteins were expressed in the myeloid cell line PLB-985. First, the correct localization of p67GFP and GFP-Rac2 was shown during ... More
Mechanisms of the genotoxicity of crocidolite asbestos in mammalian cells: implication from mutation patterns induced by reactive oxygen species.
AuthorsXu A, Zhou H, Yu DZ, Hei TK
JournalEnviron Health Perspect
PubMed ID12361925
'Asbestos is an important environmental carcinogen in the United States and remains the primary occupational concern in many developing countries; however, the underlying mechanisms of its genotoxicity are not known. We showed previously that asbestos is a potent gene and chromosomal mutagen in mammalian cells and that it induces mostly ... More
Autocrine growth factor regulation of lysyl oxidase expression in transformed fibroblasts.
AuthorsPalamakumbura AH, Sommer P, Trackman PC
JournalJ Biol Chem
PubMed ID12788924
'Lysyl oxidase catalyzes oxidative deamination of peptidyl-lysine and hydroxylysine residues in collagens and lysine residues in elastin to form peptidyl aldehydes that are required for the formation of covalent cross-links in normal extracellular matrix biosynthesis. Lysyl oxidase in addition has tumor suppressor activity, and phenotypic reversion of transformed cell lines ... More
Activation of human acid sphingomyelinase through modification or deletion of C-terminal cysteine.
AuthorsQiu H, Edmunds T, Baker-Malcolm J, Karey KP, Estes S, Schwarz C, Hughes H, Van Patten SM
JournalJ Biol Chem
PubMed ID12801930
'One form of Niemann-Pick disease is caused by a deficiency in the enzymatic activity of acid sphingomyelinase. During efforts to develop an enzyme replacement therapy based on a recombinant form of human acid sphingomyelinase (rhASM), purified preparations of the recombinant enzyme were found to have substantially increased specific activity if ... More
Cholesterol distribution in the Golgi complex of DITNC1 astrocytes is differentially altered by fresh and aged amyloid beta-peptide-(1-42).
AuthorsIgbavboa U, Pidcock JM, Johnson LN, Malo TM, Studniski AE, Yu S, Sun GY, Wood WG
JournalJ Biol Chem
PubMed ID12584199
'The Golgi complex plays an important role in cholesterol trafficking in cells, and amyloid beta-peptides (Abetas) alter cholesterol trafficking. The hypothesis was tested that fresh and aged Abeta-(1-42) would differentially modify Golgi cholesterol content in DINTC1 astrocytes and that the effects of Abeta-(1-42) would be associated with the region of ... More
Enzymatic characterization of the pancreatic islet-specific glucose-6-phosphatase-related protein (IGRP).
AuthorsPetrolonis AJ, Yang Q, Tummino PJ, Fish SM, Prack AE, Jain S, Parsons TF, Li P, Dales NA, Ge L, Langston SP, Schuller AG, An WF, Tartaglia LA, Chen H, Hong SB
JournalJ Biol Chem
PubMed ID14722102
'Glucose is the main physiological stimulus for insulin biosynthesis and secretion by pancreatic beta-cells. Glucose-6-phosphatase (G-6-Pase) catalyzes the dephosphorylation of glucose-6-phosphate to glucose, an opposite process to glucose utilization. G-6-Pase activity in pancreatic islets could therefore be an important factor in the control of glucose metabolism and, consequently, of glucose-dependent ... More
Shift in the localization of sites of hydrogen peroxide production in brain mitochondria by mitochondrial stress.
AuthorsGyulkhandanyan AV, Pennefather PS
JournalJ Neurochem
PubMed ID15228597
'We have determined the underlying sites of H(2)O(2) generation by isolated rat brain mitochondria and how these can shift depending on the presence of respiratory substrates, electron transport chain modulators and exposure to stressors. H(2)O(2) production was determined using the fluorogenic Amplex red and peroxidase system. H(2)O(2) production was higher ... More
Cellular membrane composition defines A beta-lipid interactions.
AuthorsWaschuk SA, Elton EA, Darabie AA, Fraser PE, McLaurin JA
JournalJ Biol Chem
PubMed ID11438533
'Alzheimer''s disease pathology has demonstrated amyloid plaque formation associated with plasma membranes and the presence of intracellular amyloid-beta (A beta) accumulation in specific vesicular compartments. This suggests that lipid composition in different compartments may play a role in A beta aggregation. To test this hypothesis, we have isolated cellular membranes ... More
'Many areas of research today are based on enzymatic assays most of which are still performed as enzyme-linked immunosorbent assays in microtiter plates. The demand for highly parallel screening of thousands of samples eventually led to a miniaturization and automation of these assays. However, the final transfer of enzymatic assays ... More
Novel role for apolipoprotein E in the central nervous system. Modulation of sulfatide content.
'It has long been postulated that apolipoprotein E (apoE) may play a role in lipid metabolism in the brain. However, direct evidence that apoE plays such a role is lacking. We investigated whether apoE isoforms influence lipid content in the brain. We compared the brains of wild-type mice to apoE ... More
Doxorubicin increases intracellular hydrogen peroxide in PC3 prostate cancer cells.
'We studied the effect of doxorubicin on the production of hydrogen peroxide by PC3 human prostate cancer cells, using a sensitive assay based on aminotriazole-mediated inhibition of catalase. PC3 cells exposed to increasing concentrations of doxorubicin had an increase in intracellular hydrogen peroxide that was concentration-dependent up to 1 microM ... More
Enhanced sensitivity and precision in an enzyme-linked immunosorbent assay with fluorogenic substrates compared with commonly used chromogenic substrates.
AuthorsMeng Y, High K, Antonello J, Washabaugh MW, Zhao Q
JournalAnal Biochem
PubMed ID16137635
'Quantitative enzyme-linked immunosorbent assay (ELISA) is a widely used tool for analyzing biopharmaceutical and vaccine products. The superior sensitivity of the ELISA format is conferred by signal amplification through the enzymatic oxidation or hydrolysis of substrates to products with enhanced color or fluorescence. The extinction coefficient for a colored product ... More
CXCR4 function requires membrane cholesterol: implications for HIV infection.
AuthorsNguyen DH, Taub D
JournalJ Immunol
PubMed ID11937572
'HIV requires cholesterol and lipid rafts on target cell membranes for infection. To elucidate a possible mechanism, we determined that cholesterol extraction by hydroxypropyl-beta-cyclodextrin (BCD) inhibits stromal cell-derived factor 1alpha (SDF-1alpha) binding to CXCR4 on T cell lines and PBMCs. Intracellular calcium responses to SDF-1alpha, as well as receptor internalization, ... More
Quinone biogenesis: Structure and mechanism of PqqC, the final catalyst in the production of pyrroloquinoline quinone.
AuthorsMagnusson OT, Toyama H, Saeki M, Rojas A, Reed JC, Liddington RC, Klinman JP, Schwarzenbacher R
JournalProc Natl Acad Sci U S A
PubMed ID15148379
'The biosynthesis of pyrroloquinoline quinone (PQQ), a vitamin and redox cofactor of quinoprotein dehydrogenases, is facilitated by an unknown pathway that requires the expression of six genes, pqqA to -F. PqqC, the protein encoded by pqqC, catalyzes the final step in the pathway in a reaction that involves ring cyclization ... More
Oxygen tolerance and coupling of mitochondrial electron transport.
AuthorsCampian JL, Qian M, Gao X, Eaton JW
JournalJ Biol Chem
PubMed ID15328348
'Oxygen is critical to aerobic metabolism, but excessive oxygen (hyperoxia) causes cell injury and death. An oxygen-tolerant strain of HeLa cells, which proliferates even under 80% O2, termed "HeLa-80," was derived from wild-type HeLa cells ("HeLa-20") by selection for resistance to stepwise increases of oxygen partial pressure. Surprisingly, antioxidant defenses ... More
Role for influenza virus envelope cholesterol in virus entry and infection.
AuthorsSun X, Whittaker GR
JournalJ Virol
PubMed ID14610177
'Enveloped viruses are highly dependent on their lipid envelopes for entry into and infection of host cells. Here, we have examined the role of cholesterol in the virus envelope, using methyl-beta-cyclodextrin depletion. Pretreatment of virions with methyl-beta-cyclodextrin efficiently depleted envelope cholesterol from influenza virus and significantly reduced virus infectivity in ... More
Antibody catalysis of the oxidation of water.
AuthorsWentworth P, Jones LH, Wentworth AD, Zhu X, Larsen NA, Wilson IA, Xu X, Goddard WA, Janda KD, Eschenmoser A, Lerner RA
JournalScience
PubMed ID11546867
'Recently we reported that antibodies can generate hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*). We now show that this process is catalytic, and we identify the electron source for a quasi-unlimited generation of H2O2. Antibodies produce up to 500 mole equivalents of H2O2 from 1O2*, without a reduction in ... More
Increased H(2)O(2) counteracts the vasodilator and natriuretic effects of superoxide dismutation by tempol in renal medulla.
AuthorsChen YF, Cowley AW, Zou AP
JournalAm J Physiol Regul Integr Comp Physiol
PubMed ID12791586
'A membrane-permeable SOD mimetic, 4-hydroxytetramethyl-piperidine-1-oxyl (tempol), has been used as an antioxidant to prevent hypertension. We recently found that this SOD mimetic could not prevent development of hypertension induced by inhibition of renal medullary SOD with diethyldithiocarbamic acid. The present study tested a hypothesis that increased H2O2 counteracts the effects ... More
Caveolin-induced activation of the phosphatidylinositol 3-kinase/Akt pathway increases arsenite cytotoxicity.
AuthorsShack S, Wang XT, Kokkonen GC, Gorospe M, Longo DL, Holbrook NJ
JournalMol Cell Biol
PubMed ID12640124
'The inhibitory effect of caveolin on the cellular response to growth factor stimulation is well established. Given the significant overlap in signaling pathways involved in regulating cell proliferation and stress responsiveness, we hypothesized that caveolin would also affect a cell''s ability to respond to environmental stress. Here we investigated the ... More
Characterization of the oxidase activity in mammalian catalase.
'Catalase is a highly conserved heme-containing antioxidant enzyme known for its ability to degrade hydrogen peroxide into water and oxygen. In low concentrations of hydrogen peroxide, the enzyme also exhibits peroxidase activity. We report that mammalian catalase also possesses oxidase activity. This activity, which is detected in purified catalases, cell ... More
CD36, a class B scavenger receptor, is expressed on microglia in Alzheimer's disease brains and can mediate production of reactive oxygen species in response to beta-amyloid fibrils.
'A pathological hallmark of Alzheimer''s disease is the senile plaque, composed of beta-amyloid fibrils, microglia, astrocytes, and dystrophic neurites. We reported previously that class A scavenger receptors mediate adhesion of microglia and macrophages to beta-amyloid fibrils and oxidized low-density lipoprotein (oxLDL)-coated surfaces. We also showed that CD36, a class B ... More
Chromate-reducing properties of soluble flavoproteins from Pseudomonas putida and Escherichia coli.
AuthorsAckerley DF, Gonzalez CF, Park CH, Blake R, Keyhan M, Matin A
JournalAppl Environ Microbiol
PubMed ID14766567
'Cr(VI) (chromate) is a toxic, soluble environmental contaminant. Bacteria can reduce chromate to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of interest. Genetic and protein engineering of suitable enzymes can improve bacterial bioremediation. Many bacterial enzymes catalyze one-electron reduction of chromate, generating Cr(V), which redox cycles, ... More
Glucose localization in maize ovaries when kernel number decreases at low water potential and sucrose is fed to the stems.
AuthorsMcLaughlin JE, Boyer JS
JournalAnn Bot (Lond)
PubMed ID15159218
'BACKGROUND AND AIMS: Around the time of anthesis, young ovary development in maize (Zea mays) is vulnerable to 2 or 3 d of water deficits that inhibit photosynthesis. Abortion can result, and fewer kernels are produced. A breakdown of stored ovary starch is associated with the abortion and was investigated ... More
O2 delivery and redox state are determinants of compartment-specific reactive O2 species in myocardial reperfusion.
AuthorsStoner JD, Clanton TL, Aune SE, Angelos MG
JournalAm J Physiol Heart Circ Physiol
PubMed ID17028160
'Reperfusion of the ischemic myocardium leads to a burst of reactive O(2) species (ROS), which is a primary determinant of postischemic myocardial dysfunction. We tested the hypothesis that early O(2) delivery and the cellular redox state modulate the initial myocardial ROS production at reperfusion. Isolated buffer-perfused rat hearts were loaded ... More
H2O2 is an important mediator of UVB-induced EGF-receptor phosphorylation in cultured keratinocytes.
AuthorsPeus D, Vasa RA, Meves A, Pott M, Beyerle A, Squillace K, Pittelkow MR
JournalJ Invest Dermatol
PubMed ID9620307
'Exposure of human keratinocytes to physiologic doses of ultraviolet B (UVB) radiation induces phosphorylation of the epidermal growth factor receptor (EGFR). We demonstrate that H2O2 generated by UVB mediates EGFR phosphorylation. Using dihydrorhodamine 123 as a specific fluorescent dye probe, we show that UVB irradiation (50-800 J per m2) of ... More
Discovery of acetyl-coenzyme A carboxylase 2 inhibitors: comparison of a fluorescence intensity-based phosphate assay and a fluorescence polarization-based ADP Assay for high-throughput screening.
AuthorsLiu Y, Zalameda L, Kim KW, Wang M, McCarter JD,
JournalAssay Drug Dev Technol
PubMed ID17477831
'Acetyl-coenzyme A carboxylase (ACC) enzymes exist as two isoforms, ACC1 and ACC2, which play critical roles in fatty acid biosynthesis and oxidation. Though each isoform differs in tissue and subcellular localization, both catalyze the biotin- and ATP-dependent carboxylation of acetyl-coenzyme A to generate malonyl-coenzyme A, a key metabolite in the ... More
Galactose oxidase action on galactose containing glycolipids--a fluorescence method.
AuthorsFortelius M, Mattjus P
JournalChem Phys Lipids
PubMed ID16647698
'Features that alter the glycolipid sugar headgroup accessibility at the membrane interface have been studied in bilayer lipid model vesicles using a fluorescence technique with the enzyme galactose oxidase. The effects on oxidation caused by variation in the hydrophobic moiety of galactosylceramide or the membrane environment for galactosylceramide, monogalactosyldiacylglycerol and ... More
A fluorometric assay for detection of lysyl oxidase enzyme activity in biological samples.
AuthorsPalamakumbura AH, Trackman PC
JournalAnal Biochem
PubMed ID11779117
'Lysyl oxidase catalyzes the final known enzymatic step required for collagen and elastin cross-linking in the biosynthesis of normal mature functional insoluble extracellular matrices. In addition, lysyl oxidase has been identified as a possible tumor suppressor. Lysyl oxidase activity in biological samples is traditionally and most reliably assessed by tritium ... More
Quantitative relationship between inhibition of respiratory complexes and formation of reactive oxygen species in isolated nerve terminals.
AuthorsSipos I, Tretter L, Adam-Vizi V
JournalJ Neurochem
PubMed ID12485407
'In this study reactive oxygen species (ROS) generated in the respiratory chain were measured and the quantitative relationship between inhibition of the respiratory chain complexes and ROS formation was investigated in isolated nerve terminals. We addressed to what extent complex I, III and IV,respectively, should be inhibited to cause ROS ... More
'Huntington disease (HD) is caused by a pathological elongation of CAG repeats in the huntingtin protein gene and is characterized by atrophy and neuronal loss primarily in the striatum. Mitochondrial dysfunction and impaired Ca2+ homeostasis in HD have been suggested previously. Here, we elucidate the effects of Ca2+ on mitochondria ... More
Motor deficit in a Drosophila model of mucolipidosis type IV due to defective clearance of apoptotic cells.
'Disruption of the Transient Receptor Potential (TRP) mucolipin 1 (TRPML1) channel results in the neurodegenerative disorder mucolipidosis type IV (MLIV), a lysosomal storage disease with severe motor impairments. The mechanisms underlying MLIV are poorly understood and there is no treatment. Here, we report a Drosophila MLIV model, which recapitulates the ... More
Role of endothelial nitric oxide synthase in endothelial activation: insights from eNOS knockout endothelial cells.
AuthorsKuhlencordt PJ, Rosel E, Gerszten RE, Morales-Ruiz M, Dombkowski D, Atkinson WJ, Han F, Preffer F, Rosenzweig A, Sessa WC, Gimbrone MA, Ertl G, Huang PL
JournalAm J Physiol Cell Physiol
PubMed ID15075219
'The objective of this study was to determine whether absence of endothelial nitric oxide synthase (eNOS) affects the expression of cell surface adhesion molecules in endothelial cells. Murine lung endothelial cells (MLECs) were prepared by immunomagnetic bead selection from wild-type and eNOS knockout mice. Wild-type cells expressed eNOS, but eNOS ... More
Inhibition of capacitation-associated tyrosine phosphorylation signaling in rat sperm by epididymal protein Crisp-1.
AuthorsRoberts KP, Wamstad JA, Ensrud KM, Hamilton DW
JournalBiol Reprod
PubMed ID12700197
'Ejaculated sperm are unable to fertilize an egg until they undergo capacitation. Capacitation results in the acquisition of hyperactivated motility, changes in the properties of the plasma membrane, including changes in proteins and glycoproteins, and acquisition of the ability to undergo the acrosome reaction. In all mammalian species examined, capacitation ... More
P2X7 mediates superoxide production in primary microglia and is up-regulated in a transgenic mouse model of Alzheimer's disease.
AuthorsParvathenani LK, Tertyshnikova S, Greco CR, Roberts SB, Robertson B, Posmantur R
JournalJ Biol Chem
PubMed ID12551918
'Primary rat microglia stimulated with either ATP or 2''- and 3''-O-(4-benzoylbenzoyl)-ATP (BzATP) release copious amounts of superoxide (O(2)(-)*). ATP and BzATP stimulate O(2)(-)* production through purinergic receptors, primarily the P2X(7) receptor. O(2)(-)* is produced through the activation of the NADPH oxidase. Although both p42/44 MAPK and p38 MAPK were activated ... More
Sensory neurons and schwann cells respond to oxidative stress by increasing antioxidant defense mechanisms.
AuthorsVincent AM, Kato K, McLean LL, Soules ME, Feldman EL,
JournalAntioxid Redox Signal
PubMed ID19072199
'Elevated blood glucose is a key initiator of mechanisms leading to diabetic neuropathy. Increases in glucose induce acute mitochondrial oxidative stress in dorsal root ganglion (DRG) neurons, the sensory neurons normally affected in diabetic neuropathy, whereas Schwann cells are largely unaffected. We propose that activation of an antioxidant response in ... More
Physiological characterization of Haemophilus influenzae Rd deficient in its glutathione-dependent peroxidase PGdx.
AuthorsPauwels F, Vergauwen B, Van Beeumen JJ
JournalJ Biol Chem
PubMed ID14701867
'The chimeric peroxidase PGdx of Haemophilus influenzae Rd belongs to a recently identified family of thiol peroxidases capable of reducing hydrogen peroxide as well as alkylhydroperoxides by means of glutathione redox cycling. In the present study, we constructed a H. influenzae Rd strain, deficient in its PGdx encoding gene (open ... More
?-Glutamylcysteine detoxifies reactive oxygen species by acting as glutathione peroxidase-1 cofactor.
'Reactive oxygen species regulate redox-signaling processes, but in excess they can cause cell damage, hence underlying the aetiology of several neurological diseases. Through its ability to down modulate reactive oxygen species, glutathione is considered an essential thiol-antioxidant derivative, yet under certain circumstances it is dispensable for cell growth and redox ... More
Patterning enzymes inside microfluidic channels via photoattachment chemistry.
AuthorsHolden MA, Jung SY, Cremer PS
JournalAnal Chem
PubMed ID15053641
'We have developed a general method for photopatterning well-defined patches of enzymes inside a microfluidic device at any location. First, a passivating protein layer was adsorbed to the walls and floor of a poly(dimethylsiloxane)/glass microchannel. The channel was then filled with an aqueous biotin-linked dye solution. Using an Ar+/Kr+ laser, ... More
Acute and chronic changes in cholesterol modulate Na-Pi cotransport activity in OK cells.
AuthorsBreusegem SY, Halaihel N, Inoue M, Zajicek H, Lederer E, Barry NP, Sorribas V, Levi M
JournalAm J Physiol Renal Physiol
PubMed ID15769937
'We previously showed an inverse correlation between membrane cholesterol content and Na-P(i) cotransport activity during the aging process and adaptation to alterations in dietary P(i) in the rat (Levi M, Jameson DM, and van der Meer BW. Am J Physiol Renal Fluid Electrolyte Physiol 256: F85-F94, 1989). The purpose of ... More
Encapsulation of enzymes within polymer spheres to create optical nanosensors for oxidative stress.
AuthorsKim SH, Kim B, Yadavalli VK, Pishko MV
JournalAnal Chem
PubMed ID16255579
'We describe the fabrication and characterization of poly(ethylene glycol) (PEG) hydrogel spheres containing the enzyme horseradish peroxidase (HRP) for application as optical nanosensors for hydrogen peroxide. HRP was encapsulated in PEG hydrogel spheres by reverse emulsion photopolymerization, yielding spheres with a size range from 250 to 350 nm. Encapsulated HRP ... More
Inhibition of skeletal muscle S1-myosin ATPase by peroxynitrite.
AuthorsTiago T, Simão S, Aureliano M, Martín-Romero FJ, Gutiérrez-Merino C
JournalBiochemistry
PubMed ID16533063
'Exposure of myosin subfragment 1 (S1) to 3-morpholinosydnonimine (SIN-1) produced a time-dependent inhibition of the F-actin-stimulated S1 Mg(2+)-ATPase activity, reaching 50% inhibition with 46.7 +/- 8.3 microM SIN-1 for 8.7 microM S1, that is, at a SIN-1/S1 molar ratio of approximately 5.5. The inhibition was due to the peroxynitrite produced ... More
Polygalacturonase beta-subunit antisense gene expression in tomato plants leads to a progressive enhanced wound response and necrosis in leaves and abscission of developing flowers.
AuthorsOrozco-Cárdenas ML, Ryan CA
JournalPlant Physiol
PubMed ID12972668
'Tomato (Lycopersicon esculentum var. Better Boy) plants were transformed with a tomato leaf wound-inducible polygalacturonase (PG) beta-subunit gene in the antisense orientation (PGbetaS-AS) under the control of the cauliflower mosaic virus 35S promoter. The leaves of the transgenic plants exhibited small localized lesions, which eventually enlarged and spread throughout the ... More
The ferroxidase activity of yeast frataxin.
AuthorsPark S, Gakh O, Mooney SM, Isaya G
JournalJ Biol Chem
PubMed ID12149269
'Frataxin is required for maintenance of normal mitochondrial iron levels and respiration. The mature form of yeast frataxin (mYfh1p) assembles stepwise into a multimer of 840 kDa (alpha(48)) that accumulates iron in a water-soluble form. Here, two distinct iron oxidation reactions are shown to take place during the initial assembly ... More
A highly sensitive fluorescent micro-assay of H2O2 release from activated human leukocytes using a dihydroxyphenoxazine derivative.
'This study describes a simple, reliable, highly sensitive and quantitative fluorescence microplate-assay of H2O2 from activated leukocytes using a novel horse radish peroxidase (HRP) substrate N-acetyl-3,7-dihydroxyphenoxazine (A6550). Unlike the widely used fluorescent HRP substrate scopoletin, A6550 is non-fluorescent and becomes highly fluorescent upon HRP-catalyzed H2O2 oxidation. Using 50 microM A6550, ... More
Mitochondria play no roles in Mn(II)-induced apoptosis in HeLa cells.
AuthorsOubrahim H, Stadtman ER, Chock PB
JournalProc Natl Acad Sci U S A
PubMed ID11493712
'Manganese(II) has been shown to exhibit catalase-like activity under physiological conditions. In the course of studies to test the antioxidant activity of Mn(II) on HeLa cells, it was observed at high concentrations (1-2 mM) that Mn(II) also induced apoptosis, as judged by changes in cell morphology, caspase-3 activation, cleavage of ... More
Hyperoxia-induced NAD(P)H oxidase activation and regulation by MAP kinases in human lung endothelial cells.
AuthorsParinandi NL, Kleinberg MA, Usatyuk PV, Cummings RJ, Pennathur A, Cardounel AJ, Zweier JL, Garcia JG, Natarajan V
JournalAm J Physiol Lung Cell Mol Physiol
PubMed ID12388366
'Hyperoxia increases reactive oxygen species (ROS) production in vascular endothelium; however, the mechanisms involved in ROS generation are not well characterized. We determined the role and regulation of NAD(P)H oxidase in hyperoxia-induced ROS formation in human pulmonary artery endothelial cells (HPAECs). Exposure of HPAECs to hyperoxia for 1, 3, and ... More
Glutathione and catalase provide overlapping defenses for protection against respiration-generated hydrogen peroxide in Haemophilus influenzae.
AuthorsVergauwen B, Pauwels F, Van Beeumen JJ
JournalJ Bacteriol
PubMed ID12949108
'Glutathione is an abundant and ubiquitous low-molecular-weight thiol that may play a role in many cellular processes, including protection against the deleterious effects of reactive oxygen species. We address here the role of glutathione in protection against hydrogen peroxide (H2O2) in Haemophilus influenzae and show that glutathione and catalase provide ... More
A critical investigation of NADPH oxidase activity in human spermatozoa.
AuthorsRicher SC, Ford WC
JournalMol Hum Reprod
PubMed ID11228243
'It has been suggested that human spermatozoa contain an NADPH oxidase that could generate reactive oxygen species involved in signalling pathways to promote fertility. The proposal depends on observations that the addition of NADPH to purified human spermatozoa stimulates chemiluminescence by the superoxide (O2-) probe, lucigenin. We confirmed these observations, ... More
The role of cholesterol and glycosylphosphatidylinositol-anchored proteins of erythrocyte rafts in regulating raft protein content and malarial infection.
AuthorsSamuel BU, Mohandas N, Harrison T, McManus H, Rosse W, Reid M, Haldar K
JournalJ Biol Chem
PubMed ID11352913
'Human erythrocytes are terminally differentiated, nonendocytic cells that lack all intracellular organelles. Here we show that their plasma membranes contain detergent-resistant membrane rafts that constitute a small fraction (4%) of the total membrane protein, with a complex mixture of proteins that differentially associate with rafts. Depletion of raft-cholesterol abrogates association ... More
Mitochondrial ATP-sensitive potassium channels inhibit apoptosis induced by oxidative stress in cardiac cells.
AuthorsAkao M, Ohler A, O'Rourke B, Marbán E
JournalCirc Res
PubMed ID11420303
'Mitochondria can either enhance or suppress cell death. Cytochrome c release from mitochondria and depolarization of the mitochondrial membrane potential (DeltaPsi) are crucial events in triggering apoptosis. In contrast, activation of mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels prevents lethal ischemic injury in vivo, implicating these channels as key players in the ... More
Lipopolysaccharides induced increases in Fas ligand expression by Kupffer cells via mechanisms dependent on reactive oxygen species.
AuthorsUchikura K, Wada T, Hoshino S, Nagakawa Y, Aiko T, Bulkley GB, Klein AS, Sun Z
JournalAm J Physiol Gastrointest Liver Physiol
PubMed ID15087279
'Fas-Fas ligand (FasL)-dependent pathways exert a suppressive effect on inflammatory responses in immune-privileged organs. FasL expression in hepatic Kupffer cells (KC) has been implicated in hepatic immunoregulation. In this study, modulation of FasL expression of KC by endogenous gut-derived bacterial LPS and the role of reactive oxygen species (ROS) as ... More
Roles of catalase and hydrogen peroxide in green tea polyphenol-induced chemopreventive effects.
AuthorsYamamoto T, Lewis J, Wataha J, Dickinson D, Singh B, Bollag WB, Ueta E, Osaki T, Athar M, Schuster G, Hsu S
JournalJ Pharmacol Exp Ther
PubMed ID14569057
'The green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) possesses promising anticancer potential. Although in vivo studies unveiled the metabolic routes and pharmacokinetics of EGCG and showed no adverse effects, in vitro studies at high concentrations demonstrated oxidative stress. EGCG causes differential oxidative environments in tumor versus normal epithelial cells, but the roles ... More
Characterization of superoxide-producing sites in isolated brain mitochondria.
'Mitochondrial respiratory chain complexes I and III have been shown to produce superoxide but the exact contribution and localization of individual sites have remained unclear. We approached this question investigating the effects of oxygen, substrates, inhibitors, and of the NAD+/NADH redox couple on H2O2 and superoxide production of isolated mitochondria ... More
Antibodies have the intrinsic capacity to destroy antigens.
AuthorsWentworth AD, Jones LH, Wentworth P, Janda KD, Lerner RA
JournalProc Natl Acad Sci U S A
PubMed ID11005865
'Research throughout the last century has led to a consensus as to the strategy of the humoral component of the immune system. The essence is that, for killing, the antibody molecule activates additional systems that respond to antibody-antigen union. We now report that the immune system seems to have a ... More
Quantitative structure-activity relationship and complex network approach to monoamine oxidase A and B inhibitors.
AuthorsSantana L, González-Díaz H, Quezada E, Uriarte E, Yáñez M, Viña D, Orallo F,
JournalJ Med Chem
PubMed ID18834112
'The work provides a new model for the prediction of the MAO-A and -B inhibitor activity by the use of combined complex networks and QSAR methodologies. On the basis of the obtained model, we prepared and assayed 33 coumarin derivatives, and the theoretical prediction was compared with the experimental activity ... More
Synthesis, stereochemical identification, and selective inhibitory activity against human monoamine oxidase-B of 2-methylcyclohexylidene-(4-arylthiazol-2-yl)hydrazones.
AuthorsChimenti F, Maccioni E, Secci D, Bolasco A, Chimenti P, Granese A, Carradori S, Alcaro S, Ortuso F, Yáñez M, Orallo F, Cirilli R, Ferretti R, La Torre F,
JournalJ Med Chem
PubMed ID18666768
'A series of 2-methylcyclohexylidene-(4-arylthiazol-2-yl)hydrazones have been investigated for their ability to inhibit selectively the activity of the human A and B isoforms of monoamine oxidase (MAO). The target compounds, which present a stereogenic center on the cyclohexane ring, were obtained as pure (R) and (S) enantiomers by enantioselective HPLC. The ... More
Identification of a JAK2-independent pathway regulating growth hormone (GH)-stimulated p44/42 mitogen-activated protein kinase activity. GH activation of Ral and phospholipase D is Src-dependent.
AuthorsZhu T, Ling L, Lobie PE
JournalJ Biol Chem
PubMed ID12218045
'We have demonstrated here that growth hormone (GH) stimulates the formation of the active GTP-bound form of both RalA and RalB in NIH-3T3 cells. Full activation of RalA and RalB by GH required the combined activity of c-Src and JAK2, both kinases activated by GH independent of the other. Activation ... More
The role of tetrahydrobiopterin in the regulation of neuronal nitric-oxide synthase-generated superoxide.
AuthorsRosen GM, Tsai P, Weaver J, Porasuphatana S, Roman LJ, Starkov AA, Fiskum G, Pou S
JournalJ Biol Chem
PubMed ID12183447
'Tetrahydrobiopterin (H(4)B) is a critical element in the nitric-oxide synthase (NOS) metabolism of l-arginine to l-citrulline and NO(.). It has been hypothesized that in the absence of or under nonsaturating levels of L-arginine where O(2) reduction is the primary outcome of NOS activation, H(4)B promotes the generation of H(2)O(2) at ... More
A method of direct measurement for the enzymatic determination of cholesteryl esters.
AuthorsMizoguchi T, Edano T, Koshi T
JournalJ Lipid Res
PubMed ID14563821
'A direct measurement method for the enzymatic determination of cholesteryl esters (CEs) without measuring total cholesterol (TC) and free cholesterol (FC) is described. In the first step, hydrogen peroxide generated by cholesterol oxidase from FC was decomposed by catalase. In the second step, CE was measured by enzymatic determination using ... More
Kinetic isotope effect studies on the de novo rate of chromophore formation in fast- and slow-maturing GFP variants.
'The maturation process of green fluorescent protein (GFP) entails a protein oxidation reaction triggered by spontaneous backbone condensation. The chromophore is generated by full conjugation of the Tyr66 phenolic group with the heterocycle, a process that requires C-H bond scission at the benzylic carbon. We have prepared isotope-enriched protein bearing ... More
Inhibition of the Rac1 GTPase protects against nonlethal ischemia/reperfusion-induced necrosis and apoptosis in vivo.
AuthorsOzaki M, Deshpande SS, Angkeow P, Bellan J, Lowenstein CJ, Dinauer MC, Goldschmidt-Clermont PJ, Irani K
JournalFASEB J
PubMed ID10657998
'Reperfusion of ischemic tissue results in the generation of reactive oxygen species that contribute to tissue injury. The sources of reactive oxygen species in reperfused tissue are not fully characterized. We hypothesized that the small GTPase Rac1 mediates the oxidative burst in reperfused tissue and thereby contributes to reperfusion injury. ... More
Production of reactive oxygen species by mitochondria: central role of complex III.
AuthorsChen Q, Vazquez EJ, Moghaddas S, Hoppel CL, Lesnefsky EJ
JournalJ Biol Chem
PubMed ID12840017
'The mitochondrial respiratory chain is a major source of reactive oxygen species (ROS) under pathological conditions including myocardial ischemia and reperfusion. Limitation of electron transport by the inhibitor rotenone immediately before ischemia decreases the production of ROS in cardiac myocytes and reduces damage to mitochondria. We asked if ROS generation ... More
Rotenone model of Parkinson disease: multiple brain mitochondria dysfunctions after short term systemic rotenone intoxication.
AuthorsPanov A, Dikalov S, Shalbuyeva N, Taylor G, Sherer T, Greenamyre JT
JournalJ Biol Chem
PubMed ID16243845
'Chronic infusion of rotenone (Rot) to Lewis rats reproduces many features of Parkinson disease. Rot (3 mg/kg/day) was infused subcutaneously to male Lewis rats for 6 days using Alzet minipumps. Control rats received the vehicle only. Presence of 0.1% bovine serum albumin during the isolation procedure completely removed rotenone bound ... More
Increasing the oxidative stress response allows Escherichia coli to overcome inhibitory effects of condensed tannins.
AuthorsSmith AH, Imlay JA, Mackie RI
JournalAppl Environ Microbiol
PubMed ID12788743
'Tannins are plant-derived polyphenols with antimicrobial effects. The mechanism of tannin toxicity towards Escherichia coli was determined by using an extract from Acacia mearnsii (Black wattle) as a source of condensed tannins (proanthocyanidins). E. coli growth was inhibited by tannins only when tannins were exposed to oxygen. Tannins auto-oxidize, and ... More
Purification, characterization, molecular cloning, and subcellular distribution of neutral ceramidase of rat kidney.
AuthorsMitsutake S, Tani M, Okino N, Mori K, Ichinose S, Omori A, Iida H, Nakamura T, Ito M
JournalJ Biol Chem
PubMed ID11328816
'Previously, we reported two types of neutral ceramidase in mice, one solubilized by freeze-thawing and one not. The former was purified as a 94-kDa protein from mouse liver, and cloned (Tani, M., Okino, N., Mori, K., Tanigawa, T., Izu, H., and Ito, M. (2000) J. Biol. Chem. 275, 11229--11234). In ... More
Increased susceptibility of striatal mitochondria to calcium-induced permeability transition.
AuthorsBrustovetsky N, Brustovetsky T, Purl KJ, Capano M, Crompton M, Dubinsky JM
JournalJ Neurosci
PubMed ID12832508
'Mitochondria were simultaneously isolated from striatum and cortex of adult rats and compared in functional assays for their sensitivity to calcium activation of the permeability transition. Striatal mitochondria showed an increased dose-dependent sensitivity to Ca2+ compared with cortical mitochondria, as measured by mitochondrial depolarization, swelling, Ca2+ uptake, reactive oxygen species ... More
In vitro quantitation of biological superoxide and hydrogen peroxide generation.
AuthorsMessner KR, Imlay JA
JournalMethods Enzymol
PubMed ID11912927
Efficient mixing and reactions within microfluidic channels using microbead-supported catalysts.
AuthorsSeong GH, Crooks RM
JournalJ Am Chem Soc
PubMed ID12418869
A resorufin-based fluorescent assay for quantifying NADH.
AuthorsBatchelor RH, Zhou M
JournalAnal Biochem
PubMed ID12018954
Two fluorometric approaches to the measurement of dextranase activity.
AuthorsZhou M, Zhang C, Upson RH, Haugland RP
JournalAnal Biochem
PubMed ID9657889
Neutral-lipid analysis reveals elevation of acylglycerols and lack of cholesterol esters in Plasmodium falciparum-infected erythrocytes.
AuthorsNawabi P, Lykidis A, Ji D, Haldar K
JournalEukaryot Cell
PubMed ID14555495
Here we show that blood-stage Plasmodium falciparum organisms accumulate a high mass of triacylglycerol and diacylglycerol. However, we failed to detect cholesterol esters, a second neutral lipid species reported to be important for a related apicomplexan, Toxoplasma gondii. Evidence for P. falciparum and T. gondii homologues of acyl coenzyme A:diacylglycerol ... More
High-throughput screening for Hsp90 ATPase inhibitors.
AuthorsAvila C, Hadden MK, Ma Z, Kornilayev BA, Ye QZ, Blagg BS,
JournalBioorg Med Chem Lett
PubMed ID16530412
Recently, we reported a useful assay for the determination of yeast Hsp90 ATPase activity. Using this assay, high-throughput screening of approximately 10,000 compounds was performed to determine the feasibility of this assay on large scale. Results from high-throughput screening indicated that the assay was reproducible (av Z-factor = 0.80) and ... More
Measurement of reactive oxygen species in cells and mitochondria.
AuthorsArmstrong JS, Whiteman M,
JournalMethods Cell Biol
PubMed ID17445704
This chapter discusses (1) the cellular sources of ROS and their enzymatic detoxification; (2) common methods used to determine cellular and mitochondrial ROS, including chemiluminescence (CL), spin trapping, and fluorescence and enzymatic techniques; (3) common problems associated with these assays and the interpretation of data; and (4) simple protocols for ... More
Methods for detection of reactive metabolites of oxygen and nitrogen: in vitro and in vivo considerations.
AuthorsTarpey MM, Wink DA, Grisham MB
JournalAm J Physiol Regul Integr Comp Physiol
PubMed ID14761864
Facile detection of reactive oxygen and nitrogen species in biologic systems is often problematic. This is a result of the numerous cellular mechanisms, both enzymatic and nonenzymatic involved in their catabolism/decomposition, the complex and overlapping nature of their reactivities, as well as the often limited intracellular access of detector systems. ... More
Determination of phosphate in nanomolar range by an enzyme-coupling fluorescent method.
We have successfully configured a new ultrasensitive fluorescent phosphate assay that detects free phosphate in solution through the formation of the fluorescent product resorufin. The phosphate assay relies on coupling phosphate generation to purine nucleoside phosphorylase, xanthine oxidase, and horseradish peroxidase. The response is excellent in the nanomolar range, being ... More
Reactive oxygen species (ROS) are involved in many signalling pathways and numerous stress responses in plants. Consequently, it is important to be able to identify and localize ROS in vivo to evaluate their roles in signalling. A number of probes that have a high affinity for specific ROS and that ... More
Development and optimization of a useful assay for determining Hsp90's inherent ATPase activity.
AuthorsAvila C, Kornilayev BA, Blagg BS,
JournalBioorg Med Chem
PubMed ID16213144
The Hsp90 molecular chaperone is responsible for the conformational maturation of nascent polypeptides and the rematuration of denatured proteins. Inhibition of Hsp90 represents a promising approach towards the treatment of cancer because numerous signaling cascades can be simultaneously targeted by disruption of the Hsp90-mediated process. Hsp90's ATPase activity is essential ... More
Chapter 24 Quantification, localization, and tissue specificities of mouse mitochondrial reactive oxygen species production.
Mitochondria play a critical role in many different pathologic conditions. Increasing evidence has shown that mitochondrial reactive oxygen species (ROS) production may provide an etiologic link between mitochondria and pathologics. The widespread use of laboratory mice as models for a host of human diseases makes the quantification and localization of ... More
Microfluidic large-scale integration.
AuthorsThorsen T, Maerkl SJ, Quake SR
JournalScience
PubMed ID12351675
We developed high-density microfluidic chips that contain plumbing networks with thousands of micromechanical valves and hundreds of individually addressable chambers. These fluidic devices are analogous to electronic integrated circuits fabricated using large-scale integration. A key component of these networks is the fluidic multiplexor, which is a combinatorial array of binary ... More
A reagent less fluorescent sol-gel biosensor for uric acid detection in biological fluids.
AuthorsMartinez-Pérez D, Ferrer ML, Mateo CR
JournalAnal Biochem
PubMed ID14596833
The simultaneous encapsulation of a coupled uricase-peroxidase system and amplex red in a sol-gel matrix allows one to obtain a reagent-less and ready-to-use fluorescent biosensor for the accurate detection of uric acid in highly diluted biological fluids. The detection limit of the prepared biosensor was found to be 20 nM ... More
CNS synaptogenesis promoted by glia-derived cholesterol.
AuthorsMauch DH, Nägler K, Schumacher S, Göritz C, Müller EC, Otto A, Pfrieger FW
JournalScience
PubMed ID11701931
The molecular mechanisms controlling synaptogenesis in the central nervous system (CNS) are poorly understood. Previous reports showed that a glia-derived factor strongly promotes synapse development in cultures of purified CNS neurons. Here, we identify this factor as cholesterol complexed to apolipoprotein E-containing lipoproteins. CNS neurons produce enough cholesterol to survive ... More
Glutathione peroxidase-like activity of caeruloplasmin as an important lung antioxidant.
AuthorsPark YS, Suzuki K, Taniguchi N, Gutteridge JM
JournalFEBS Lett
PubMed ID10481051
The copper-containing plasma protein caeruloplasmin (Cp) has been shown to possess several oxidase activities, but with the exception of its ferrous ion oxidising (ferroxidase) activity which so far appear to be of minor biological relevance. Recently, Kim and colleagues (Kim et al. (1998) FEBS Lett. 431, pp. 473-475) observed that ... More