Linked Life Data

9880548

Source:http://linkedlifedata.com/resource/pubmed/id/9880548

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-2-11
pubmed:abstractText
A recent proposal for the formation of functionally active rhodopsin has placed critical importance on a movement of one of its transmembrane helices (Farrens, D. L., Altenbach, C., Yang, K., Hubbell, W. L., and Khorana, H. G. (1996) Science 274, 768-770). We investigated this hypothesis using a series of eight rhodopsin mutants containing single reactive cysteine residues in the region (helix F) where movement was previously detected. The cysteine mutants were studied in two ways, by measuring their reactivity to a cysteine-specific reagent (PyMPO-maleimide), and by labeling the cysteines with a fluorescent label (monobromobimane) followed by fluorescence spectroscopic analysis. The chemical reactivity data showed sequence-specific variations in reactivity for the mutants in the dark state, resulting in a pattern suggestive of an alpha helix. Interestingly, only upon photoactivation to the MII form did residues found on the inner "face" of this helix react with the PyMPO-maleimide. The ability of the dark state mutants to react with the fluorescent label monobromobimane followed a similar pattern. Furthermore, fluorescence measurements indicate that a bimane label on the inner face of the helix (at V250C) detects changes in the polarity of its environment and accessibility to a fluorescence quenching agent upon MII formation. Viewed together, the data provide further direct evidence that rhodopsin activation involves a conformational change at helix F.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1683-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Conformational changes in rhodopsin. Movement of helix f detected by site-specific chemical labeling and fluorescence spectroscopy.
pubmed:affiliation
Departments of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland, Oregon 97201-3098, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.