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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
2
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pubmed:dateCreated |
1999-5-26
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pubmed:abstractText |
As we previously reported, synaptic vesicles isolated from sheep brain cortex contain a Ca2+/H+ antiport that permits Ca2+ accumulation inside the vesicles ( approximately 5 nmol/mg protein) at expenses of the pH gradient generated by the H+-pumping ATPase. We observed that the system associates Ca2+ influx to H+ release and operates with low affinity for Ca2+. In the present work, we found that Ca2+/H+ antiport mediates exchange of protons with other cations such as Zn2+ and Cd2+, suggesting that these cations and Ca2+ share the same transporter molecules to enter the intravesicular space. Zn2+ and Cd2+ induce H+ release in a concentration-dependent manner (fluorimetrically evaluated) and they inhibit the antiport-mediated Ca2+ uptake by the vesicles (isotopically measured). In contrast, large cations such as Ba2+ and Cs+ do not alter Ca2+ influx and they are unable to induce proton release from the vesicles. With respect to Sr2+, which has an intermediary size relatively to the other groups of cations, we found that it does not induce H+ liberation from the vesicles, but it has a concentration-dependent inhibitory effect on the Ca2+-induced H+ release and Ca2+ uptake by the vesicles. These results indicate that the cation selectivity of the synaptic vesicles Ca2+/H+ antiport is essentially determined by the size of the cation transported into the vesicles.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Antiporters,
http://linkedlifedata.com/resource/pubmed/chemical/Barium,
http://linkedlifedata.com/resource/pubmed/chemical/Cadmium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Carbonyl Cyanide m-Chlorophenyl...,
http://linkedlifedata.com/resource/pubmed/chemical/Cation Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Ionophores,
http://linkedlifedata.com/resource/pubmed/chemical/Protons,
http://linkedlifedata.com/resource/pubmed/chemical/Strontium,
http://linkedlifedata.com/resource/pubmed/chemical/Zinc,
http://linkedlifedata.com/resource/pubmed/chemical/calcium-hydrogen antiporters,
http://linkedlifedata.com/resource/pubmed/chemical/carbonylcyanide...
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0169-328X
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pubmed:author |
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pubmed:copyrightInfo |
Copyright 1999 Elsevier Science B.V.
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pubmed:issnType |
Print
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pubmed:day |
20
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pubmed:volume |
67
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
283-91
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:10216226-Adenosine Triphosphate,
pubmed-meshheading:10216226-Animals,
pubmed-meshheading:10216226-Antiporters,
pubmed-meshheading:10216226-Barium,
pubmed-meshheading:10216226-Biological Transport,
pubmed-meshheading:10216226-Cadmium,
pubmed-meshheading:10216226-Calcium,
pubmed-meshheading:10216226-Calcium-Binding Proteins,
pubmed-meshheading:10216226-Carbonyl Cyanide m-Chlorophenyl Hydrazone,
pubmed-meshheading:10216226-Cation Transport Proteins,
pubmed-meshheading:10216226-Cerebral Cortex,
pubmed-meshheading:10216226-Electrophysiology,
pubmed-meshheading:10216226-Ion Channel Gating,
pubmed-meshheading:10216226-Ionophores,
pubmed-meshheading:10216226-Protons,
pubmed-meshheading:10216226-Sheep,
pubmed-meshheading:10216226-Strontium,
pubmed-meshheading:10216226-Synaptic Transmission,
pubmed-meshheading:10216226-Synaptic Vesicles,
pubmed-meshheading:10216226-Zinc
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pubmed:year |
1999
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pubmed:articleTitle |
Ionic selectivity of the Ca2+/H+ antiport in synaptic vesicles of sheep brain cortex.
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pubmed:affiliation |
Centro de Biologia Celular, Departamento de Biologia, Universidade de Aveiro, 3810 Aveiro, Portugal. pgoncalves@bio.ua.pt
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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