Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
|
| pubmed:dateCreated |
1998-10-21
|
| pubmed:abstractText |
Immobilized calcium affinity chromatography was used to obtain a preparation enriched in calcium transporters from Triton X-100 extracts of rat liver mitochondria inner membranes (PPCT). The PPCT were reconstituted into preformed asolectin liposomes which contained 120 mM KCl as internal high K+ medium. 45Ca2+ uptake into proteoliposomes was studied under conditions favoring electrophoretic uptake, and H+i/45Ca2+o or Na+i/45Ca2+o exchange, to test for the presence of the three calcium transport modes present in mitochondria. 45Ca2+ uptake in liposomes was studied in parallel. Na+i/45Ca2+o exchange activity was not detectable. H+i/45Ca2+o exchange activity measured in the presence of a pH gradient (acid inside) obtained after suspension in low K medium in the presence of nigericin, was 100-200 nmoles 45Ca2+ per mg protein in 30 s. 45Ca2+ uptake in voltage-dependent assays (a K+ diffusion membrane potential induced by valinomycin in the presence of methylamine) was not electrophoretic since it was stimulated by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and probably due to secondary Ca2+/H+ countertransport. H+i/45Ca2+o uptake showed a saturable component at around 80 microM Ca and was coupled to an increase in internal pH in pyranine-loaded PPCT proteoliposomes. 45Ca2+ uptake in PPCT proteoliposomes could also be driven by a pH gradient obtained by raising external pH in high K+ medium. The results are consistent with the presence of a functional nH+/Ca2+ antiporter. Polyclonal antibodies raised against the PPCT were able to immunoprecipitate the H+/45Ca2+ uptake activity and recognized two major bands in the PPCT with molecular masses of about 66 kDa and 55 kDa. This is the first report of a partial purified protein(s) which may represent the H+/Ca2+ exchanger of the inner mitochondrial membrane, and represents an important step towards its identification.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antiporters,
http://linkedlifedata.com/resource/pubmed/chemical/Arylsulfonates,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Carbonyl Cyanide...,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Cation Transport Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Liposomes,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Octoxynol,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylcholines,
http://linkedlifedata.com/resource/pubmed/chemical/Phospholipids,
http://linkedlifedata.com/resource/pubmed/chemical/Valinomycin,
http://linkedlifedata.com/resource/pubmed/chemical/asolectin,
http://linkedlifedata.com/resource/pubmed/chemical/calcium-hydrogen antiporters,
http://linkedlifedata.com/resource/pubmed/chemical/pyranine
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Sep
|
| pubmed:issn |
0006-3002
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
2
|
| pubmed:volume |
1373
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
347-59
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:9733995-Animals,
pubmed-meshheading:9733995-Antiporters,
pubmed-meshheading:9733995-Arylsulfonates,
pubmed-meshheading:9733995-Calcium,
pubmed-meshheading:9733995-Calcium Radioisotopes,
pubmed-meshheading:9733995-Calcium-Binding Proteins,
pubmed-meshheading:9733995-Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone,
pubmed-meshheading:9733995-Carrier Proteins,
pubmed-meshheading:9733995-Cation Transport Proteins,
pubmed-meshheading:9733995-Chromatography, Affinity,
pubmed-meshheading:9733995-Hydrogen-Ion Concentration,
pubmed-meshheading:9733995-Kinetics,
pubmed-meshheading:9733995-Liposomes,
pubmed-meshheading:9733995-Membrane Proteins,
pubmed-meshheading:9733995-Microscopy, Electron,
pubmed-meshheading:9733995-Mitochondria, Liver,
pubmed-meshheading:9733995-Octoxynol,
pubmed-meshheading:9733995-Phosphatidylcholines,
pubmed-meshheading:9733995-Phospholipids,
pubmed-meshheading:9733995-Rats,
pubmed-meshheading:9733995-Valinomycin
|
| pubmed:year |
1998
|
| pubmed:articleTitle |
Affinity chromatography purification of mitochondrial inner membrane proteins with calcium transport activity.
|
| pubmed:affiliation |
Departamento de Biología Molecular, Centro de Biología Molecular 'Severo Ochoa', C.S.I.C.-Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049-Madrid, Spain.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|