Linked Life Data

9791943

Source:http://linkedlifedata.com/resource/pubmed/id/9791943

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-11-18
pubmed:abstractText
Electrogenic ion transport by the Na,K-ATPase was investigated in a model system of protein-containing membrane fragments adsorbed to a lipid bilayer. Transient Na+ currents were induced by photorelease of ATP from inactive caged ATP. This process was accompanied by a capacitance change of the membrane system. Two methods were applied to measure capacitances in the frequency range 1 to 6000 Hz. The frequency dependent capacitance increment, delta C, was of sigmoidal shape and decreased at high frequencies. The midpoint frequency, f0, depended on the ionic strength of the buffer. At 150 mM NaCl f0 was about 200 Hz and decreased to 12 Hz at high ionic strength (1 M). At low frequencies (f << f0) the capacitance increment became frequency independent. It was, however, dependent on Na+ concentration and on the membrane potential which was generated by the charge transferred. A simple model is presented to analyze the experimental data quantitatively as a function of two parameters, the capacitance of the adsorbed membrane fragments, Cp, and the potential of maximum capacitance increment, psi 0. Below 5 mM Na+ a negative capacitance change was detected which may be assigned to electrogenic Na+ binding to cytoplasmic sites. It could be shown that the results obtained by experiments with the presented alternating current method contain the information which is determined by current-relaxation experiments with cell membranes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0175-7571
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
605-17
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Influence of sodium concentration on changes of membrane capacitance associated with the electrogenic ion transport by the Na,K-ATPase.
pubmed:affiliation
Frumkin Institute of Electrochemistry, Moscow, Russia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't