title: [Conformational transitions in Na, K-dependent ATPase].
abstract: Conformational transitions in membrane preparations of Na, K-dependent ATPase were studied by means of mono-radical and bi-radical hydrophobic spine probes. A decrease in micro-viscosity of non-polar membrane regions in Na, K-ATPase preparation was observed under the formation of phosphorylated N, K-ATPase intermediate in the presence of ATP and Na+ ions. K+-catalysed dephosphorylation of the intermediate resulted in opposite changes. Bi-radical probes of a certain chemical structure turned to be the most sensitive indicators of conformational changes in membranes of Na, K-ATPase preparation. Na+-, K+- and ATP-induced conformational transitions are blocked with suabaine, a specific inhibitor of Na, K-ATPase, with Ca2+ oligomycin and p-chloromercuric benzoate (PCMB). K+-dependent transitions are more sensitive to oligomycin and PCMB as compared with those induced by ATP and Na+. Possible mechanisms of conformational transitions in Na, K-dependent ATPase are discussed.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D004794:Enzyme Repression / Q000187:drug effects; D005609:Free Radicals; D006168:Guinea Pigs; D007668:Kidney / Q000201:enzymology; D008433:Mathematics; D008968:Molecular Conformation; D009840:Oligomycins / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013113:Spin Labels / Q000138:chemical synthesis; D014783:Viscosity
chemical_list: D002729:Chloromercuribenzoates; D005609:Free Radicals; D009840:Oligomycins; D013113:Spin Labels; D012965:Sodium Chloride; D010042:Ouabain; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium
vernacular_title: Konformatsionnye perekhody v Na, K-zavisimoĭ ATPaze