Linked Life Data

2145156

Source:http://linkedlifedata.com/resource/pubmed/id/2145156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-11-21
pubmed:abstractText
Unidirectional Ca2+ fluxes (influx and efflux), supported by ATP as a phosphate-donor substrate, were measured without alteration of the lumenal Ca2+ content in longitudinal sarcoplasmic reticulum vesicles. The referred fluxes are dependent on extravesicular Ca2+, ATP and ADP. They are unaffected by ruthenium red but inhibited by quercetin. The Ca2+ fluxes at steady state are drastically diminished when ATP is substituted by acetylphosphate although the addition of 10 microM ADP increases the apparent rate constants more than eight fold. The observed fluxes appear to be dependent on Ca2(+)-ATPase phosphoenzyme transitions. The results indicate that: (a) the slow Ca2+ release, due to the passive permeability of the membrane, is a minor component of the total Ca2+ efflux, and (b) the ATPase protein is basically operating as a Ca2+/Ca2+ exchanger at steady state. Kinetic resolution of the Ca2+ fluxes, measured by isotopic tracer and rapid filtration techniques can be recreated by computer simulation of the ATPase reaction cycle featuring some modifications to account for the fast Ca2+/Ca2+ exchange and the uncoupling effect observed at steady state.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
192
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
347-54
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Characterization of the steady-state calcium fluxes in skeletal sarcoplasmic reticulum vesicles. Role of the Ca2+ pump.
pubmed:affiliation
Departamento de Bioquimica y Biologia Molecular, Facultad de Veterinaria, Universidad de Murcia, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't