Kinetic studies on interaction of (Na,K)-ATPase with Cibacron Blue F3GA as probe of the nucleotide fold.
Cibacron Blue F3GA (Cb) effectively and reversibly inhibits the activity of (Na,K)-ATPase. Its inhibitory effect does not occur through occupation of the ouabain binding site, but presumably results from Cb-occupation of one catalytic site not competitively attracting ATP. Cb also inhibits ouabain binding to (Na,K)-ATPase. Its inhibitory effect is competitively antagonized by ATP proving accommodation of Cb in the ATP binding site. - If one admits Cb as a suitable analytical tool for the detection of a supersecondary structure folding pattern, the findings suggest that the ATP binding site is lined by beta-pleated sheets flanked by alpha-helices thus providing an environment that funnels ATP to the catalytic site.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D004396:Coloring Agents / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007700:Kinetics; D010042:Ouabain / Q000378:metabolism; D011487:Protein Conformation; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014227:Triazines / Q000494:pharmacology*
D004396:Coloring Agents; D014227:Triazines; D010042:Ouabain; C012842:Cibacron Blue F 3GA; D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase