Identification and characterization of sulfhydryl-containing proteolytic fragments involved in the Ca2+-induced conformational change of beef brain S-100.
The Ca2+-dependent conformational alteration of the brain-specific S-100 protein was studied by reacting the protein with N-ethyl[2,3-14C]maleimide in the absence and presence of Ca2+ and under denaturing conditions. Peptic hydrolysates of the 14C-labeled protein were analyzed and fractionated by high-performance liquid chromatography. Labeled peptide fractions were characterized by high-voltage electrophoresis and TLC. A clear distinction could be made between two classes of sulfhydryl-containing fragments: (a) neutral, hydrophobic, and (b) acidic. Ca2+ markedly favored 14C incorporation into the former components, whereas the latter were readily available only under denaturing conditions.
D000818:Animals; D002118:Calcium; D002250:Carbon Radioisotopes; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004228:Dithionitrobenzoic Acid; D005033:Ethylmaleimide; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000032:analysis; D009778:Occipital Lobe / Q000648:ultrastructure; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D011487:Protein Conformation; D009418:S100 Proteins / Q000032:analysis; D013438:Sulfhydryl Compounds / Q000032:analysis
D002250:Carbon Radioisotopes; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D009418:S100 Proteins; D013438:Sulfhydryl Compounds; D004228:Dithionitrobenzoic Acid; D005033:Ethylmaleimide; D002118:Calcium