Mostrar el registro sencillo del ítem

dc.contributor.author
Montes, Monica Raquel
dc.contributor.author
Monti, José Luis Eugenio
dc.contributor.author
Rossi, Rolando Carlos
dc.date.available
2017-06-14T19:43:12Z
dc.date.issued
2012-09
dc.identifier.citation
Montes, Monica Raquel; Monti, José Luis Eugenio; Rossi, Rolando Carlos; E2→E1 transition and Rb+ release induced by Na+ in the Na+/K+-ATPase. Vanadate as a tool to investigate the interaction between Rb+ and E2; Elsevier Science; Biochimica et Biophysica Acta - Biomembranes; 1818; 9; 9-2012; 2087-2093
dc.identifier.issn
0005-2736
dc.identifier.uri
http://hdl.handle.net/11336/18197
dc.description.abstract
This work presents a detailed kinetic study that shows the coupling between the E2→E1 transition and Rb+ deocclusion stimulated by Na+ in pig-kidney purified Na,K-ATPase. Using rapid mixing techniques, we measured in parallel experiments the decrease in concentration of occluded Rb+ and the increase in eosin fluorescence (the formation of E1) as a function of time. The E2→E1 transition and Rb+ deocclusion are described by the sum of two exponential functions with equal amplitudes, whose rate coefficients decreased with increasing [Rb+]. The rate coefficient values of the E2→E1 transition were very similar to those of Rb+-deocclusion, indicating that both processes are simultaneous. Our results suggest that, when ATP is absent, the mechanism of Na+-stimulated Rb+ deocclusion would require the release of at least one Rb+ ion through the extracellular access prior to the E2→E1 transition. Using vanadate to stabilize E2, we measured occluded Rb+ in equilibrium conditions. Results show that, while Mg2 + decreases the affinity for Rb+, addition of vanadate offsets this effect, increasing the affinity for Rb+. In transient experiments, we investigated the exchange of Rb+ between the E2-vanadate complex and the medium. Results show that, in the absence of ATP, vanadate prevents the E2→E1 transition caused by Na+ without significantly affecting the rate of Rb+ deocclusion. On the other hand, we found the first evidence of a very low rate of Rb+ occlusion in the enzyme–vanadate complex, suggesting that this complex would require a change to an open conformation in order to bind and occlude Rb+.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier Science
dc.rights
info:eu-repo/semantics/restrictedAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.subject
Na+/K+-Atpase
dc.subject
Conformational Transition
dc.subject
Rb+-Deocclusion
dc.subject
Vanadate
dc.subject.classification
Biofísica
dc.subject.classification
Ciencias Biológicas
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
E2→E1 transition and Rb+ release induced by Na+ in the Na+/K+-ATPase. Vanadate as a tool to investigate the interaction between Rb+ and E2
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2017-06-14T14:35:58Z
dc.journal.volume
1818
dc.journal.number
9
dc.journal.pagination
2087-2093
dc.journal.pais
Países Bajos
dc.journal.ciudad
Ámsterdam
dc.description.fil
Fil: Montes, Monica Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina
dc.description.fil
Fil: Monti, José Luis Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina
dc.description.fil
Fil: Rossi, Rolando Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina
dc.journal.title
Biochimica et Biophysica Acta - Biomembranes
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/ark/http://www.sciencedirect.com/science/article/pii/S000527361200123X
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/j.bbamem.2012.04.001


Archivos asociados

Documento no disponible

Comunidades y colecciones

  • Articulos(IQUIFIB) [344]
    Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"

Mostrar el registro sencillo del ítem