dc.creator | Montes, Monica Raquel | |
dc.creator | Spiaggi, Alejandro Javier | |
dc.creator | Monti, José Luis Eugenio | |
dc.creator | Cornelius, Flemming | |
dc.creator | Olesen, Claus | |
dc.creator | Garrahan, Patricio Jose | |
dc.creator | Rossi, Rolando Carlos | |
dc.date.accessioned | 2017-06-14T18:51:10Z | |
dc.date.available | 2017-06-14T18:51:10Z | |
dc.date.created | 2017-06-14T18:51:10Z | |
dc.date.issued | 2011-01 | |
dc.identifier | Montes, Monica Raquel; Spiaggi, Alejandro Javier; Monti, José Luis Eugenio; Cornelius, Flemming; Olesen, Claus; et al.; Rb+ occlusion stabilized by vanadate in gastric H+/K+-ATPase at 25 ºC; Elsevier Science; Biochimica et Biophysica Acta - Biomembranes; 1808; 1; 1-2011; 316-322 | |
dc.identifier | 0005-2736 | |
dc.identifier | http://hdl.handle.net/11336/18186 | |
dc.identifier | CONICET Digital | |
dc.identifier | CONICET | |
dc.description.abstract | Despite its similarity with the Na+/K+-ATPase, it has not been possible so far to isolate a K+-occluded state in the H+/K+-ATPase at room temperature. We report here results on the time course of formation of a state containing occluded Rb+ (as surrogate for K+) in H+/K+-ATPase from gastric vesicles at 25 °C. Alamethicin (a pore-forming peptide) showed to be a suitable agent to open vesicles, allowing a more efficient removal of Rb+ ions from the intravesicular medium than C12E8 (a non-ionic detergent). In the presence of vanadate and Mg2+, the time course of [86Rb]Rb+ uptake displayed a fast phase due to Rb+ occlusion. The specific inhibitor of the H+/K+-ATPase SCH28080 significantly reduces the amount of Rb+ occluded in the vanadate–H+/K+-ATPase complex. Occluded Rb+ varies with [Rb+] according to a hyperbolic function with K0.5 = 0.29 ± 0.06 mM. The complex between the Rb+-occluded state and vanadate proved to be very stable even after removal of free Mg2+ with EDTA. Our results yield a stoichiometry lower than one occluded Rb+ per phosphorylation site, which might be explained assuming that, unlike for the Na+/K+-ATPase, Mg2+-vanadate is unable to recruit all the Rb+-bound to the Rb+-occluded form of the Rb+–vanadate–H+/K+-ATPase complex. | |
dc.language | eng | |
dc.publisher | Elsevier Science | |
dc.relation | info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0005273610003032 | |
dc.relation | info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/j.bbamem.2010.08.022 | |
dc.rights | https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ | |
dc.rights | info:eu-repo/semantics/openAccess | |
dc.subject | H+/K+-Atpase | |
dc.subject | Rb+-Occlusion | |
dc.subject | Gastric Vesicles | |
dc.subject | Alamethicin | |
dc.subject | Vanadate | |
dc.title | Rb+ occlusion stabilized by vanadate in gastric H+/K+-ATPase at 25 ºC | |
dc.type | info:eu-repo/semantics/article | |
dc.type | info:ar-repo/semantics/artículo | |
dc.type | info:eu-repo/semantics/publishedVersion | |