Linked Life Data

6271177

Source:http://linkedlifedata.com/resource/pubmed/id/6271177

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1982-1-20
pubmed:abstractText
The dependence of proton movement across the membrane of bacteriorhodopsin liposomes on the pH gradient was investigated. Under the appropriate experimental conditions, endogenous proton (or hydroxyl) leakage, proton movement catalyzed by protonophore or nigericin, and light-driven proton translocation depend linearly on the pH gradient. This justifies the use of linear proton flux vs. protonmotive force relations in a recent mosaic thermodynamic description of ion translocation in bacteriorhodopsin liposomes [Westerhoff, H. V., Scholte, B. J., & Hellingwerf, K. J. (1979) Biochim. Biophys. Acta 547, 544-560]. Since bacteriorhodopsin liposomes are a model system for all biological energy transducing systems in which proton pumps are involved, these findings also explain linear relations between proton flux and protonmotive force observed in and postulated for those systems. In cases where the membrane potential is not clamped at a low value, an initial phase of rapid proton movement occurs, followed by a phase of slower proton movement. The rate of proton movement during the slow phase is again linear with the pH gradient. Such a linear relation is not observed for the fast phase. Since the rapid proton movement phase is also observed in liposomes without bacteriorhodopsin, it is not due (only) to dissociation of scalar protons from bacteriorhodopsin. We suggest that during the initial phase of proton movement, the proton flux is not yet electrically compensated by the fluxes of other ions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5114-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Linear relations between proton current and pH gradient in bacteriorhodopsin liposomes.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't