(Na+ + K+)-ATPase: inactivation and degradation induced by oxygen radicals.
1. Purified (Na+ + K+)-ATPase was irreversibly inhibited upon exposure to hydrogen peroxide, the superoxide anion, and the hydroxyl radical. 2. Comparison of the SDS-gel electrophoretic patterns of the ATPase samples exposed to these oxidants revealed that inhibition occurred either without gross structural changes, or concomitant with fragmentation and cross-linking of the enzyme subunits. 3. The oxidant modified ATPase was also shown to be more susceptible to degradation by several proteolytic enzymes.
Huang
W H
WH
Department of Pharmacology, Medical College of Ohio, Toledo 43699-0008.
Wang
Y
Y
Askari
A
A
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D004285:Dogs; D005296:Ferrous Compounds / Q000494:pharmacology; D005609:Free Radicals; D007700:Kinetics; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000494:pharmacology; D019820:Xanthine; D014969:Xanthine Oxidase / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D005296:Ferrous Compounds; D005609:Free Radicals; D014361:Trypsin Inhibitors; D014970:Xanthines; D019820:Xanthine; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D000254:Sodium-Potassium-Exchanging ATPase; D001205:Ascorbic Acid; D010100:Oxygen