The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase

Autores
Gonzalez-Lebrero, Rodolfo Martin; Kaufman, Sergio Benjamín; Garrahan, Patricio Jose; Rossi, Rolando Carlos
Año de publicación
2008
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
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.
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
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
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
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
Materia
sidedness of occlusion
Na/K-ATPase
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/138158
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/138158
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPaseGonzalez-Lebrero, Rodolfo MartinKaufman, Sergio BenjamínGarrahan, Patricio JoseRossi, Rolando Carlossidedness of occlusionNa/K-ATPasehttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1Occlusion 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.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; ArgentinaFil: 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; ArgentinaFil: 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; ArgentinaFil: 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; ArgentinaAmerican Chemical Society2008-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/138158Gonzalez-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; 6073-60800006-2960CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/bi800270kinfo:eu-repo/semantics/altIdentifier/doi/10.1021/bi800270kinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:47:15Zoai:ri.conicet.gov.ar:11336/138158instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:47:15.723CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
title The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
spellingShingle The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
Gonzalez-Lebrero, Rodolfo Martin
sidedness of occlusion
Na/K-ATPase
title_short The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
title_full The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
title_fullStr The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
title_full_unstemmed The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
title_sort The pathway for spontaneous occlusion of Rb+ in the Na +/K+-ATPase
dc.creator.none.fl_str_mv Gonzalez-Lebrero, Rodolfo Martin
Kaufman, Sergio Benjamín
Garrahan, Patricio Jose
Rossi, Rolando Carlos
author Gonzalez-Lebrero, Rodolfo Martin
author_facet Gonzalez-Lebrero, Rodolfo Martin
Kaufman, Sergio Benjamín
Garrahan, Patricio Jose
Rossi, Rolando Carlos
author_role author
author2 Kaufman, Sergio Benjamín
Garrahan, Patricio Jose
Rossi, Rolando Carlos
author2_role author
author
author
dc.subject.none.fl_str_mv sidedness of occlusion
Na/K-ATPase
topic sidedness of occlusion
Na/K-ATPase
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv 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.
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
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
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
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
description 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.
publishDate 2008
dc.date.none.fl_str_mv 2008-12
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/138158
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
0006-2960
CONICET Digital
CONICET
url http://hdl.handle.net/11336/138158
identifier_str_mv 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
0006-2960
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/bi800270k
info:eu-repo/semantics/altIdentifier/doi/10.1021/bi800270k
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.070432

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