Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2008-11-21
pubmed:abstractText
H(+)-pumping rhodopsins mediate a primordial conversion of light to metabolic energy. Bacteriorhodopsin from Halobacterium salinarium is the first identified and (biochemically) best-studied H(+)-pumping rhodopsin. The electrical properties of H(+)-pumping rhodopsins, however, are known in more detail for the homolog Acetabularia rhodopsin, isolated from the eukaryotic green alga Acetabularia acetabulum. Based on data from Acetabularia rhodopsin we present a general reaction kinetic model of H(+)-pumping rhodopsins with only seven independent parameters, which fits the kinetic properties of photocurrents as functions of light, transmembrane voltage, internal and external pH, and time. The model describes fast photoisomerization of retinal with simultaneous H(+) transfer to an H(+) acceptor, reprotonation of retinal from the intracellular face via an H(+) donor, and proton release to the extracellular space via an H(+) release complex. The voltage sensitivities of the individual reaction steps and their temporal changes are treated here by a novel approach, whereby--as in an Ohmic voltage divider--the effective portions of the total transmembrane voltage decrease with the relative velocities of the individual reaction steps. This analysis quantitatively infers dynamic changes of the voltage profile and of the pK values of the H(+)-binding sites involved.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-1001456, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10026285, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10352029, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10352030, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10452895, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10514362, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10747201, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10777732, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10777733, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10984592, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-10988064, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-11545597, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-11566778, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-11580403, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-12770869, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-12893935, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-13771349, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-14525004, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-14532280, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-14747309, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-14765197, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15327290, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15465857, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15731388, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15756587, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15817390, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-15860584, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16241693, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16376293, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16731558, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16761083, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16780789, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-16854162, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17177428, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17243153, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17488114, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17690293, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17704179, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-17872961, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-272644, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-6275448, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-6278476, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-8543064, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-9425071, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-963073, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-9649365, http://linkedlifedata.com/resource/pubmed/commentcorrection/18621842-9761483
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1542-0086
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5005-13
pubmed:dateRevised
2010-9-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Dynamics of voltage profile in enzymatic ion transporters, demonstrated in electrokinetics of proton pumping rhodopsin.
pubmed:affiliation
Humboldt-Universität zu Berlin, Fachbereich für Biologie, Experimentelle Biophysik, Berlin, Germany. rolf.hagedorn@rz.hu-berlin.de
pubmed:publicationType
Journal Article