Lipid-protein interactions mediate the photochemical function of rhodopsin
- 23 August 1988
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 27 (17), 6469-6474
- https://doi.org/10.1021/bi00417a041
Abstract
We have investigated the molecular features of recombinant membranes that are necessary for the photochemical function of rhodopsin. The magnitude of the metarhodopsin I to metarhodopsin II phototransient following a 25% .+-. 3% bleaching flash was used as a criterion of photochemical activity at 28.degree.C and pH 7.0. Nativelike activity of rhodopsin can be reconstituted with an extract of total lipids from rod outer segment membranes, demonstrating that the protein is minimally perturbed by the reconstitution protocol. Rhodopsin photochemical activity is enhanced by phosphatidylethanolamine head groups and docosahexaenoyl (22:6.omega.3) acyl chains. An equimolar mixture of phosphatidylethanolamine and phosphatidylcholine containing 50 mol % docosahexaenoyl chains results in optimal photochemical function. These results suggest the importance of both the head-group and acyl chain composition of the rod outer segment lipids in the visual process. The extracted rod lipids and those lipid mixtures favoring the conformational change from metarhodopsin I to II can undergo lamellar (L.alpha.) to inverted hexagonal (HII) phase transitions near physiological temperature. Interaction of rhodopsin with membrane lipids close to a L.alpha. to HII (or cubic) phase boundary may thus lead to properties which influence the energetics of conformational states of the protein linked to visual function.This publication has 20 references indexed in Scilit:
- A method for the synthesis of isomerically pure saturated mixed-chain phosphatidylcholinesAnalytical Biochemistry, 1981
- Rhodopsin-phospholipid interactions: dependence of rate of the meta I to meta II transition on the level of associated disk phospholipidBiochemistry, 1981
- Rhodopsin-lipid associations in bovine rod outer segment membranes. Identification of immobilized lipid by spin-labelsBiochemistry, 1979
- Disaturated and dipolyunsaturated phospholipids in the bovine retinal rod outer segment disk membraneBiochimica et Biophysica Acta (BBA) - Biomembranes, 1979
- A reinvestigation of the fatty acid content of bovine, rat and frog retinal rod outer segmentsExperimental Eye Research, 1979
- Photochemical functionality of rhodopsin-phospholipid recombinant membranesBiochemistry, 1977
- Transphosphatidylation by Phospholipase DJournal of Biological Chemistry, 1967
- Fatty acid and fatty aldehyde composition of the major brain lipids in normal human gray matter, white matter, and myelinJournal of Lipid Research, 1965
- Chromatographically homogeneous lecithin from egg phospholipidsJournal of Oil & Fat Industries, 1965
- Tautomeric Forms of MetarhodopsinThe Journal of general physiology, 1963