Linked Life Data

8003504

Source:http://linkedlifedata.com/resource/pubmed/id/8003504

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1994-7-21
pubmed:abstractText
The photoreactions of rhodopsin regenerated with three 9-cis retinal analogs, modified at or in the vicinity of the beta-ionone ring (namely 5,6-epoxy, 7,8-diH, diethyl-acyclic) have been investigated by UV-vis and FTIR difference spectroscopy. In parallel, the ability to catalyze the GDP-->GTP exchange of G-protein (transducin) has been monitored by time-dependent fluorescence spectroscopy. The first photoproduct obtained with all three pigments at liquid nitrogen temperature is a blue-shifted intermediate (BSI), followed by a lumi-like intermediate at 170 K. For the 5,6-epoxy-ISO and 7,8-diH-ISO pigment we obtain two further intermediates similar to the META-I and META-II states of native RHO. For the diethyl-acyclic-ISO pigment only one further intermediate can be stabilized at 280 K. As compared to META-II the respective photoproduct exhibits striking differences. The latter two pigments have also been investigated in the solubilized lipid-free state (detergent: dodecyl maltoside) at 280 K. For the 5,6-epoxy-ISO pigment, the UV-vis, FTIR, and activation data agree with the formation of a META-II-like photoproduct (81% activation). Less META-II formation is observed for the 7,8-dihydro-ISO pigment in membranes (65% activation), but full formation in detergent (100% activation). Neither the membrane-bound nor the solubilized diethyl-acyclic-ISO pigment forms a META-II-like intermediate (18% and 0% activation, respectively). Therefore, we conclude that the substitution of the beta-ionone ring by two ethyl groups abolishes steric interactions with the protein, which are essential for META-II formation.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7389-97
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Interactions of the beta-ionone ring with the protein in the visual pigment rhodopsin control the activation mechanism. An FTIR and fluorescence study on artificial vertebrate rhodopsins.
pubmed:affiliation
Institut für Biophysik und Strahlenbiologie, Albert-Ludwigs-Universität Freiburg, FRG.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't