Linked Life Data

8188711

Source:http://linkedlifedata.com/resource/pubmed/id/8188711

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1994-6-22
pubmed:abstractText
A reconstituted proteoliposomal system was obtained with Ca-ATPase purified from human erythrocyte membrane (plasma membrane, PM ATPase), and liposomes prepared by reverse-phase evaporation. The reconstituted PM ATPase behaved as an electrogenic Ca2+/H+ exchanger and, under optimal conditions, utilization of 1 mol of ATP was accompanied by uptake of one Ca2+ by the vesicles, and ejection of one H+ from the lumen of the vesicles. Ca2+ uptake was greatly (5-fold) stimulated by the addition of calmodulin, and by collapsing the H+ gradient with the ionophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone. In the presence of calmodulin and p-trifluoromethoxyphenylhydrazone, the reconstituted system sustained transport rates of 1.00 +/- 0.12 mumol of Ca2+/mg of protein min-1 (30 degrees C), reaching asymptotic levels of 8.05 +/- 0.41 mumol of Ca2+/mg of protein (i.e. 20 mM lumenal Ca2+). The corresponding net charge transfer produced a maximal electrical gradient of 40.5 +/- 1.8 mV at steady state. Demonstration of the electrogenic behavior of the PM ATPase, obtained for the first time with these experiments, was critically dependent on the detergent used in the reconstitution procedure. The lumenal pH rise had a much greater rate-limiting effect on the pump, than the electrical potential developed by the pump.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14268-75
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Ca2+/H+ countertransport and electrogenicity in proteoliposomes containing erythrocyte plasma membrane Ca-ATPase and exogenous lipids.
pubmed:affiliation
Department of Biological Chemistry, University of Maryland School of Medicine, Baltimore 21201.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't