Lack of effect of RPE65 removal on the enzymatic processing of all‐trans‐retinol into 11‐cis‐retinol in vitro

FEBS Letters

Choo, Dong Won¹  Cheung, Eric¹  Rando, Robert R¹ 

[1] Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston MA 02115, USA

关键词: Visual cycle;    Isomerohydrolase;    RPE65;    Vitamin A;    LRAT;    lecithin retinol acyl transferase;    DTT;    dithiothreitol;    DMSO;    dimethylsulfoxide;    RPE;    retinal pigment epithelium;   

DOI  :  10.1016/S0014-5793(98)01459-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

RPE65 is a major membrane associated protein found in the vertebrate retinal pigment epithelium (RPE). Various studies have shown this protein to be essential for visual function, possibly at the level of the processing of retinoids. The pigment epithelium is the anatomical site in which the visual chromophore 11-cis retinal is generated. The two critical RPE enzymes in the isomerization pathway are lecithin retinol acyl transferase (LRAT) and isomerohydrolase, which processes all-trans-retinyl esters into 11-cis-retinol. Both enzymes are membrane bound. It is shown here that RPE65 can be largely extracted (90–95%) from RPE membranes by 1 M KCl by itself, or with added detergent CHAPS. The almost quantitative extraction of RPE65 from RPE membranes has little or no effect on in vitro LRAT and isomerohydrolase activities in quantitative enzymatic assays using RPE membranes, suggesting that RPE65 may not have an important role to play in the enzymatic processing of all-trans-retinol into 11-cis-retinol in vitro.

【 授权许可】

Unknown