Site-directed fluorescence studies of a prokaryotic ClC antiporter.
AuthorsBell SP, Curran PK, Choi S, Mindell JA
JournalBiochemistry
PubMed ID16734414
'Channels and transporters of the ClC family serve a variety of physiological functions. Understanding of their gating and transport mechanisms remains incomplete, with disagreement over the extent of protein conformational change involved. Using site-directed fluorescence labeling, we probe ClC-ec1, a prokaryotic ClC, for transport-related structural rearrangements. We specifically label cysteines ... More
Reversible glutathionylation of complex I increases mitochondrial superoxide formation.
AuthorsTaylor ER, Hurrell F, Shannon RJ, Lin TK, Hirst J, Murphy MP
JournalJ Biol Chem
PubMed ID12649289
'Increased production of reactive oxygen species (ROS) by mitochondria is involved in oxidative damage to the organelle and in committing cells to apoptosis or senescence, but the mechanisms of this increase are unknown. Here we show that ROS production by mitochondrial complex I increases in response to oxidation of the ... More
Fullerene water suspension (nC60) exerts antibacterial effects via ROS-independent protein oxidation.
AuthorsLyon DY, Alvarez PJ,
JournalEnviron Sci Technol
PubMed ID19031913
Buckminsterfullerene (C60) can form water suspensions (nC60) that exert toxic effects. While reactive oxygen species (ROS) generation has been implicated as the mechanism for mammalian cytotoxicity, we propose that nC60 exerts ROS-independent oxidative stress in bacteria, with evidence of protein oxidation, changes in cell membrane potential, and interruption of cellular ... More
A sensitive assay for maleimide groups.
AuthorsSingh R
JournalBioconjug Chem
PubMed ID7948101
A sensitive spectrophotometric assay has been developed for maleimide groups incorporated into proteins. The assay involves the reaction of maleimide with an excess of cysteine and quantitation of the remaining cysteine using an enzymatic assay that is based on the stoichiometric conversion of an inactive disulfide form of papain to ... More
An amplified assay for thiols based on reactivation of papain.
AuthorsSingh R, Blättler WA, Collinson AR
JournalAnal Biochem
PubMed ID8238881
A sensitive spectrophotometric assay has been developed for thiol (sulfhydryl) groups using an inactive disulfide derivative of papain (papain-S-SCH3). The thiol-disulfide interchange reaction of a thiol with papain-S-SCH3 results in the stoichiometric formation of active papain (papain-SH). The reactivated papain catalyzes the hydrolysis of a chromogenic substrate, resulting in an ... More
Two distinct mechanisms of nitric oxide-mediated neuronal cell death show thiol dependency.
AuthorsGow AJ, Chen Q, Gole M, Themistocleous M, Lee VM, Ischiropoulos H
JournalAm J Physiol Cell Physiol
PubMed ID10837337
To better understand the mechanism(s) underlying nitric oxide (. NO)-mediated toxicity, in the presence and absence of concomitant oxidant exposure, postmitotic terminally differentiated NT2N cells, which are incapable of producing. NO, were exposed to PAPA-NONOate (PAPA/NO) and 3-morpholinosydnonimine (SIN-1). Exposure to SIN-1, which generated peroxynitrite in the range of 25-750 ... More
Structure of human Wilson protein domains 5 and 6 and their interplay with domain 4 and the copper chaperone HAH1 in copper uptake.
Human Wilson protein is a copper-transporting ATPase located in the secretory pathway possessing six N-terminal metal-binding domains. Here we focus on the function of the metal-binding domains closest to the vesicular portion of the copper pump, i.e., domain 4 (WLN4), and a construct of domains 5 and 6 (WLN5-6). For ... More
Development of sulfhydryl-reactive silica for protein immobilization in high-performance affinity chromatography.
AuthorsMallik R, Wa C, Hage DS
JournalAnal Chem
PubMed ID17297940
Two techniques were developed for the immobilization of proteins and other ligands to silica through sulfhydryl groups. These methods made use of maleimide-activated silica (the SMCC method) or iodoacetyl-activated silica (the SIA method). The resulting supports were tested for use in high-performance affinity chromatography by employing human serum albumin (HSA) ... More
Evaluation of methods for the quantitation of cysteines in proteins.
AuthorsWright SK, Viola RE
JournalAnal Biochem
PubMed ID9866701
Several methods for the quantitation of cysteines in proteins have been evaluated and compared. Titration of protein sulfhydryl groups with 5,5'-dithiobis(2-nitrobenzoate) (DTNB) under carefully controlled conditions has extended the detection limits of this method with high accuracy and reproducibility. Results are reported for a variety of enzymes containing a range ... More
Spectral, kinetic, and thermodynamic properties of Cu(I) and Cu(II) binding by methanobactin from Methylosinus trichosporium OB3b.
AuthorsChoi DW, Zea CJ, Do YS, Semrau JD, Antholine WE, Hargrove MS, Pohl NL, Boyd ES, Geesey GG, Hartsel SC, Shafe PH, McEllistrem MT, Kisting CJ, Campbell D, Rao V, de la Mora AM, Dispirito AA
JournalBiochemistry
PubMed ID16445286
To examine the potential role of methanobactin (mb) as the extracellular component of a copper acquisition system in Methylosinus trichosporium OB3b, the metal binding properties of mb were examined. Spectral (UV-visible, fluorescence, and circular dichroism), kinetic, and thermodynamic data suggested copper coordination changes at different Cu(II):mb ratios. Mb appeared to ... More
Effects of biological oxidants on the catalytic activity and structure of group VIA phospholipase A2.
AuthorsSong H, Bao S, Ramanadham S, Turk J
JournalBiochemistry
PubMed ID16700550
Group VIA phospholipase A(2) (iPLA(2)beta) is expressed in phagocytes, vascular cells, pancreatic islet beta-cells, neurons, and other cells and plays roles in transcriptional regulation, cell proliferation, apoptosis, secretion, and other events. A bromoenol lactone (BEL) suicide substrate used to study iPLA(2)beta functions inactivates iPLA(2)beta by alkylating Cys thiols. Because thiol ... More
rA1M-035, a Physicochemically Improved Human Recombinant α1-Microglobulin, Has Therapeutic Effects in Rhabdomyolysis-Induced Acute Kidney Injury.
Authors
JournalAntioxid Redox Signal
PubMed ID29471681
Serum Protein Thiol Levels in Patients with Hospital-Acquired Acute Kidney Injury.
Authors
JournalKidney Blood Press Res
PubMed ID26672792
Gadolinium Tagged Osteoprotegerin-Mimicking Peptide: A Novel Magnetic Resonance Imaging Biospecific Contrast Agent for the Inhibition of Osteoclastogenesis and Osteoclast Activity.
Authors
JournalNanomaterials (Basel)
PubMed ID29865247
13C NMR detects conformational change in the 100-kD membrane transporter ClC-ec1.