Artículo
Alternative cycling modes of the Na+/K+-ATPase in the presence of either Na+ or Rb+
Fecha de publicación:
05/2013
Editorial:
Elsevier
Revista:
Biochimica And Biophysica Acta
ISSN:
0006-3002
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
A comprehensive study of the interaction between Na+ and K+ with the Na+/K+-ATPase requires dissecting the incidence of alternative cycling modes on activity measurements in which one or both of these cations are absent. With this aim, we used membrane fragments containing pig-kidney Na+/K+-ATPase to perform measurements, at 25ºC and pH=7.4, of ATPase activity and steady state levels of (i) intermediates containing occluded Rb+ at different [Rb+] in media lacking Na+, and (ii) phosphorylated intermediates at different [Na+] in media lacking Rb+. Most relevant results are: (1) Rb+ can be occluded through an ATPasic cycling mode that takes place in the absence of Na+ ions, (2) the kinetic behavior of the phosphoenzyme formed by ATP in the absence of Na+ is different from the one that is formed with Na+, and (3) binding of Na+ to transport sites during catalysis is not at random unless rapid equilibrium holds.
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Articulos(IQUIFIB)
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Citación
Monti, José Luis Eugenio; Rossi, Rolando Carlos; Montes, Monica Raquel; Alternative cycling modes of the Na+/K+-ATPase in the presence of either Na+ or Rb+; Elsevier; Biochimica And Biophysica Acta; 1828; 5; 5-2013; 1374-1383
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