title: [Interaction of spin labels and probes with Na+,K+-ATPase].
abstract: Localization of the PCMB-R spin label and benzocarboline probe bound with the purified preparation of pig kidney-Na+, K(+)-ATPase relative to active site of the enzyme was studied by EPR method. The number of Mn2+ ions in active site of the enzyme as well as that bound with lipids was determined from EPR spectra of paramagnetic manganese ions replacing magnesium ions were measured in frozen protein samples of Na2+, K(+)-ATPase at 77 K. It has been found that sulfhydryl group of the enzyme modified by PCMB-R and benzocarboline probe are placed at distances 38 A and 50 A, respectively, from Mn2+ ions in the active site of Na+, K(+)-ATPase. Evaluation of the immersion depth of the nitroxyl radical into protein globule showed that benzocarboline probe was immobilized near the macromolecular protein surface; there are two bound probe sites, distinguished by accessibility of ferricyanide ions.
authors.forename: A V
authors.initials: AV
authors.lastname: Kulikov
authors.forename: F T
authors.initials: FT
authors.lastname: Umarova
authors.forename: G I
authors.initials: GI
authors.lastname: Likhtenshteĭn
mesh_terms: D000818:Animals; D001665:Binding Sites; D002243:Carbolines / Q000737:chemistry*; D002729:Chloromercuribenzoates / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D007668:Kidney / Q000201:enzymology*; D008345:Manganese / Q000737:chemistry; D015335:Molecular Probes; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D013113:Spin Labels; D013552:Swine; D020245:p-Chloromercuribenzoic Acid
chemical_list: D002243:Carbolines; D002729:Chloromercuribenzoates; D015335:Molecular Probes; D013113:Spin Labels; D008345:Manganese; D020245:p-Chloromercuribenzoic Acid; D000254:Sodium-Potassium-Exchanging ATPase
vernacular_title: Issledovanie vzaimodeĭstviia spinovykh metok i zondov s Na+,K+-ATPazoĭ.