Publication Date:
2000-06-24
Description:
Movement of the ligand/receptor complex in rhodopsin (Rh) has been traced. Bleaching of diazoketo rhodopsin (DK-Rh) containing 11-cis-3-diazo-4-oxo-retinal yields batho-, lumi-, meta-I-, and meta-II-Rh intermediates corresponding to those of native Rh but at lower temperatures. Photoaffinity labeling of DK-Rh and these bleaching intermediates shows that the ionone ring cross-links to tryptophan-265 on helix F in DK-Rh and batho-Rh, and to alanine-169 on helix D in lumi-, meta-I-, and meta-II-Rh intermediates. It is likely that these movements involving a flip-over of the chromophoric ring trigger changes in cytoplasmic membrane loops resulting in heterotrimeric guanine nucleotide-binding protein (G protein) activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Borhan, B -- Souto, M L -- Imai, H -- Shichida, Y -- Nakanishi, K -- GM34509/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Jun 23;288(5474):2209-12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Columbia University, New York, NY 10027, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10864869" target="_blank"〉PubMed〈/a〉
Keywords:
Affinity Labels
;
Azo Compounds/chemistry/*metabolism
;
Binding Sites
;
Circular Dichroism
;
Heterotrimeric GTP-Binding Proteins/metabolism
;
Ligands
;
Light
;
Models, Molecular
;
Photolysis
;
Protein Binding
;
Protein Conformation
;
Protein Structure, Secondary
;
Retinaldehyde/analogs & derivatives/chemistry/*metabolism
;
Rhodopsin/*analogs & derivatives/chemistry/*metabolism
;
Rod Cell Outer Segment/*metabolism
;
Stereoisomerism
;
Temperature
;
*Vision, Ocular
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
