'Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, ... More
Amplex UltraRed enhances the sensitivity of fluorimetric pyruvate detection.
AuthorsZhu A, Romero R, Petty HR,
JournalAnal Biochem
PubMed ID20382105
Pyruvate, which is produced in the final step of glycolysis, participates in anabolic metabolism, catabolic metabolism, and signal transduction. We have recently reported a new sensitive and selective fluorimetric assay for pyruvate measurement using Amplex Red as a fluorogenic dye. However, the fluorescence of the reaction product, resorufin, is pH ... More
Ultrahigh-throughput screening in drop-based microfluidics for directed evolution.
AuthorsAgresti JJ, Antipov E, Abate AR, Ahn K, Rowat AC, Baret JC, Marquez M, Klibanov AM, Griffiths AD, Weitz DA,
JournalProc Natl Acad Sci U S A
PubMed ID20142500
The explosive growth in our knowledge of genomes, proteomes, and metabolomes is driving ever-increasing fundamental understanding of the biochemistry of life, enabling qualitatively new studies of complex biological systems and their evolution. This knowledge also drives modern biotechnologies, such as molecular engineering and synthetic biology, which have enormous potential to ... More
Resveratrol promotes clearance of Alzheimer's disease amyloid-beta peptides.
AuthorsMarambaud P, Zhao H, Davies P,
JournalJ Biol Chem
PubMed ID16162502
Several epidemiological studies indicate that moderate consumption of wine is associated with a lower incidence of Alzheimer's disease. Wine is enriched in antioxidant compounds with potential neuroprotective activities. However, the exact molecular mechanisms involved in the beneficial effects of wine intake on the neurodegenerative process in Alzheimer's disease brain remain ... More
Facile SNP detection using bifunctional, cross-linking oligonucleotide probes.
AuthorsPeng X, Greenberg MM,
JournalNucleic Acids Res
PubMed ID18281702
A facile, sensitive method for detecting specific sequences of oligonucleotides was developed. Detection of DNA sequences with single nucleotide discrimination is achieved by combining the selectivity of hybridization with an efficient cross-linking reaction. Readily synthesized bifunctional oligonucleotide probes containing a modified pyrimidine that is capable of forming interstrand cross-links under ... More
Membrane potential greatly enhances superoxide generation by the cytochrome bc1 complex reconstituted into phospholipid vesicles.
AuthorsRottenberg H, Covian R, Trumpower BL,
JournalJ Biol Chem
PubMed ID19478336
The mitochondrial cytochrome bc(1) complex (ubiquinol/cytochrome c oxidoreductase) is generally thought to generate superoxide anion that participates in cell signaling and contributes to cellular damage in aging and degenerative disease. However, the isolated, detergent-solubilized bc(1) complex does not generate measurable amounts of superoxide except when inhibited by antimycin. In addition, ... More
Inhibition of mitochondrial hydrogen peroxide production by lipophilic metalloporphyrins.
AuthorsCastello PR, Drechsel DA, Day BJ, Patel M,
JournalJ Pharmacol Exp Ther
PubMed ID18063723
Many studies have established a role for oxidative stress and mitochondrial dysfunction as an important mechanism in the pathogenesis of neuronal disorders. Metalloporphyrins are a class of catalytic antioxidants that are capable of detoxifying a wide range of reactive oxygen species. The AEOL112 series of glyoxylate metalloporphyrins were designed with ... More
Regulation of interleukin-8 via an airway epithelial signaling cascade.
Airways function as an innate immune organ against airborne bacteria that are inhaled and deposited in airways. One of the mechanisms of host defense is to recruit neutrophils into airways to clear the invaders. Airway epithelial cells produce neutrophil chemoattractant interleukin (IL)-8 in response to invading bacteria. In this study ... More
Comparison of fluorescence-based techniques for the quantification of particle-induced hydroxyl radicals.
AuthorsCohn CA, Simon SR, Schoonen MA,
JournalPart Fibre Toxicol
PubMed ID18307787
ABSTRACT: BACKGROUND: Reactive oxygen species including hydroxyl radicals can cause oxidative stress and mutations. Inhaled particulate matter can trigger formation of hydroxyl radicals, which have been implicated as one of the causes of particulate-induced lung disease. The extreme reactivity of hydroxyl radicals presents challenges to their detection and quantification. Here, ... More
Diverse subcellular locations of cryptogein-induced reactive oxygen species production in tobacco Bright Yellow-2 cells.
AuthorsAshtamker C, Kiss V, Sagi M, Davydov O, Fluhr R,
JournalPlant Physiol
PubMed ID17277088
Reactive oxygen species (ROS) play a crucial role in many cellular responses and signaling pathways, including the oxidative burst defense response to pathogens. We have examined very early events in cryptogein-induced ROS production in tobacco (Nicotiana tabacum) Bright Yellow-2 suspension cells. Using Amplex Red and Amplex Ultra Red reagents, which ... More
pLG72 modulates intracellular D-serine levels through its interaction with D-amino acid oxidase: effect on schizophrenia susceptibility.
AuthorsSacchi S, Bernasconi M, Martineau M, Mothet JP, Ruzzene M, Pilone MS, Pollegioni L, Molla G,
JournalJ Biol Chem
PubMed ID18544534
Human genes coding for pLG72 and d-amino acid oxidase have recently been linked to the onset of schizophrenia. pLG72 was proposed as an activator of the human FAD-containing flavoprotein d-amino acid oxidase (hDAAO). In the brain this oxidizes d-serine, a potent activator of N-methyl-d-aspartate receptor. We have investigated the mechanistic ... More
Paraquat-induced production of reactive oxygen species in brain mitochondria.
AuthorsDrechsel DA, Patel M,
JournalMethods Enzymol
PubMed ID19348900
Paraquat (PQ) is a prototypical redox cycling agent commonly used experimentally to generate reactive oxygen species and oxidative stress. Recently, PQ has also come under investigation as a potential environmental neurotoxin associated with increased risk for neurodegenerative disease developing after chronic exposure. The interactions of PQ with mitochondria remain an ... More
Chemical genetics suggests a critical role for lysyl oxidase in zebrafish notochord morphogenesis.
AuthorsAnderson C, Bartlett SJ, Gansner JM, Wilson D, He L, Gitlin JD, Kelsh RN, Dowden J
JournalMol Biosyst
PubMed ID17216056
As a result of a chemical genetic screen for modulators of metalloprotease activity, we report that 2-mercaptopyridine-N-oxide induces a conspicuous undulating notochord defect in zebrafish embryos, a phenocopy of the leviathan mutant. The location of the chemically-induced wavy notochord correlated with the timing of application, thus defining a narrow chemical ... More
Troglitazone, a peroxisome proliferator-activated receptor-gamma agonist, decreases tau phosphorylation in CHOtau4R cells.
Authorsd'Abramo C, Ricciarelli R, Pronzato MA, Davies P
JournalJ Neurochem
PubMed ID16787414
Peroxisome proliferator-activated receptor-gamma (PPARgamma), a member of the nuclear receptor superfamily, is activated by several compounds including the thiazolidinediones. In addition to being a target for diabetes, PPARgamma activation state has recently been shown to modulate beta-amyloid peptide (Abeta) production in cellular models relevant to Alzheimer's disease. Here, we report ... More
Mitochondria are a major source of paraquat-induced reactive oxygen species production in the brain.
AuthorsCastello PR, Drechsel DA, Patel M
JournalJ Biol Chem
PubMed ID17389593
Paraquat (PQ(2+)) is a prototypic toxin known to exert injurious effects through oxidative stress and bears a structural similarity to the Parkinson disease toxicant, 1-methyl-4-pheynlpyridinium. The cellular sources of PQ(2+)-induced reactive oxygen species (ROS) production, specifically in neuronal tissue, remain to be identified. The goal of this study was to ... More