Sulfhydryl group modification of photoreceptor G‐protein prevents its light‐induced binding to rhodopsin

[摘要]

The effect of sulfhydryl modification on the light-induced interaction between rhodopsin and the peripheral GTP-binding protein of the photoreceptor membrane (G-protein) has been investigated by time-resolved near-infrared light-scattering and polyacrylamide gel electrophoresis. It has been found that the modification of rhodopsin with the alkylating agent N-ethylmaleimide (NEM) does not affect its light-induced interaction with the G-protein. Modification of G-protein with NEM or other sulfhydryl agents prevents any light-induced binding to rhodopsin. Dark-associatiion of G to the membrane as well as the light-induced complex with rhodopsin (once formed) is insensitive to NEM.

[学科分类] 生物化学/生物物理

[关键词] Sulfhydryl modification;Photoreceptor;Peripheral membrane protein;GTP-binding protein;Rhodopsin;Protein-protein interaction;ROS;rod outer segments;G;G-protein or GTP-binding protein or transducin;NIR;near infrared;R*;photoexcited rhodopsin;GTP-γS;guanosine 5′-O-(3-thiotriphosphate);DTNB;5;5′-dithiobis(2-nitrobenzoic acid);NEM;N-ethylmaleimide;2-PDS;2;2′-dithiodipyridine;DTT;dithiothreitol;Pipes;piperazine-1;4-diethanesulfonic acid