Effect of peptide bond splitting on ouabain sensitive conformational changes in Na+,K+-ATPase treated with N-[p-(2-benzimidazolyl)phenyl]maleimide.
Trypsin treatment of N-[p-(2-benzimidazolyl)phenyl]maleimide modified enzyme caused a marked reduction in Na+,K+-ATPase activity and in the amount of the alpha-chain, which contains the phosphorylation and ouabain binding sites. However, these preparations retained nearly 90% of the ouabain binding capacity and showed ouabain sensitive dynamic fluorescence changes accompanying the hydrolysis of ATP. The data showed that the three dimensional structure of Na+,K+-ATPase, which is important in the dynamic fluorescence change, is little affected in spite of extensive covalent bond splitting in the alpha-chain of Na+,K+-ATPase.
D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D066298:In Vitro Techniques; D008301:Maleimides / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology*; D010766:Phosphorylation; D011487:Protein Conformation; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D014357:Trypsin
D008301:Maleimides; C000245:N-(4-(2-benzimidazolyl)phenyl)maleimide; D010042:Ouabain; D014357:Trypsin; D000254:Sodium-Potassium-Exchanging ATPase