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dc.contributor.author
Gonzalez-Lebrero, Rodolfo Martin
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Kaufman, Sergio Benjamín
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Garrahan, Patricio Jose
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Rossi, Rolando Carlos
dc.date.available
2021-08-11T15:44:43Z
dc.date.issued
2008-12
dc.identifier.citation
Gonzalez-Lebrero, Rodolfo Martin; Kaufman, Sergio Benjamín; Garrahan, Patricio Jose; Rossi, Rolando Carlos; The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase; American Chemical Society; Biochemistry; 47; 22; 12-2008; 6073-6080
dc.identifier.issn
0006-2960
dc.identifier.uri
http://hdl.handle.net/11336/138158
dc.description.abstract
Occlusion of K+ in the Na+/K+-ATPase can be achieved under two conditions: during hydrolysis of ATP, in media with Na+ and Mg2+, after the K+-stimulated dephosphorylation of E2P (physiological route) or spontaneously, after binding of K+ to the enzyme (direct route). We investigated the sidedness of spontaneous occlusion and deocclusion of Rb+ in an unsided, purified preparation of Na+/K+-ATPase. Our studies were based on two propositions: (i) in the absence of ATP, deocclusion of K+ and its congeners is a sequential process where two ions are released according to a single file mechanism, both in the absence and in the presence of Mg 2+ plus inorganic orthophosphate (Pi), and (ii) in the presence of Mg2+ plus Pi, exchange of K+ would take place through sites exposed to the extracellular surface of the membrane. The experiments included a double incubation sequence where one of the two Rb+ ions was labeled as 86Rb+. We found that, when the enzyme is in the E2 conformation, the first Rb+ that entered the enzyme in media without Mg2+ and Pi was the last to leave after addition of Mg 2+ plus Pi, and vice-versa. This indicates that spontaneous exchange of Rb+ between E2(Rb2) and the medium takes place when the transport sites are exposed to the extracellular surface of the membrane. Our results open the question if occlusion and deocclusion via the direct route participates in any significant degree in the transport of K+ during the ATPase activity.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
American Chemical Society
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
sidedness of occlusion
dc.subject
Na/K-ATPase
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Biofísica
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Ciencias Biológicas
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CIENCIAS NATURALES Y EXACTAS
dc.title
The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2021-07-26T17:14:13Z
dc.journal.volume
47
dc.journal.number
22
dc.journal.pagination
6073-6080
dc.journal.pais
Estados Unidos
dc.description.fil
Fil: Gonzalez-Lebrero, Rodolfo Martin. 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
dc.description.fil
Fil: Kaufman, Sergio Benjamín. 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
dc.description.fil
Fil: Garrahan, Patricio Jose. 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
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
dc.journal.title
Biochemistry
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/bi800270k
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1021/bi800270k
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