title: Distribution of free sulfhydryl and disulfide groups among platelet membrane proteins.
abstract: Reactive sulfhydryl and disulfide groups were identified in platelet membrane proteins resolved by sodium dodecyl sulfate-polycrylamide gel electrophoresis. Platelet membranes treated with N-ethyl(1-14C)maleimide, phenyl(203Hg)mercuric acetate and p-chloro(203Hg)mercuribenzoate showed similar patterns of distribution of sulfhydryl groups among the sodium dodecyl sulfate-solubilized membrane proteins. Four major and two minor polypeptides ranging in molecular weight from greater than 200 000 to 20 000 were found to have reactive SH groups. Reduction of membrane proteins by sulfite coupled with subsequent mercaptide formation of the resultant monothiols led to the identification of four polypeptides with disulfide bonds. Reaction of platelet membranes with 14C-labeled 5,5'-dithio-bis(2-nitrobenzoic acid) resulted changes in the distribution profile of the solubilized membrane proteins suggestive of a polymerization process dependent upon, 5,5'-dithio-bis(2-nitrobenzoic acid)-induced intermolecular disulfide interchange.
mesh_terms: D001665:Binding Sites; D001792:Blood Platelets / Q000032:analysis*; D001798:Blood Proteins / Q000032:analysis*; D002462:Cell Membrane / Q000032:analysis*; D002729:Chloromercuribenzoates; D004220:Disulfides / Q000032:analysis; D004228:Dithionitrobenzoic Acid; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D008301:Maleimides; D008628:Mercury; D008970:Molecular Weight; D009942:Organometallic Compounds; D011485:Protein Binding; D011487:Protein Conformation; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D001798:Blood Proteins; D002729:Chloromercuribenzoates; D004220:Disulfides; D046911:Macromolecular Substances; D008301:Maleimides; D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D004228:Dithionitrobenzoic Acid; D008628:Mercury