title: Cross-linking experiments with the adenosine triphosphatase of sarcoplasmic reticulum.
abstract: The proteins of sarcoplasmic reticulum were cross-linked by rapid oxidation of thiol groups with I2. About two-thirds of the thiols were oxidized without any significant cross-linking, implying an extensive formation of intramolecular disulphide bonds. When the thiols were completely oxidized at room temperature a series of oligomers containing up to five molecules were observed, as well as large aggregates which were excluded from the gels. Complete oxidation at -10 degrees C left most of the ATPase (adenosine triphosphatase) as monomer. Similar results were obtained when copper-phenanthroline complexes or dimethyl suberimidate were used as cross-linking reagents. We conclude that most of the cross-linked species arise by linking of randomly colliding ATPase molecules which are present in the membrane at very high concentration.
mesh_terms: D000251:Adenosine Triphosphatases; D003300:Copper; D004120:Dimethyl Suberimidate; D004220:Disulfides; D007455:Iodine; D046911:Macromolecular Substances; D010084:Oxidation-Reduction; D010618:Phenanthrolines; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013438:Sulfhydryl Compounds; D014357:Trypsin
chemical_list: D004220:Disulfides; D046911:Macromolecular Substances; D010618:Phenanthrolines; D013438:Sulfhydryl Compounds; D004120:Dimethyl Suberimidate; D003300:Copper; D007455:Iodine; D014357:Trypsin; D000251:Adenosine Triphosphatases