ATP-independent deactivation of squid rhodopsin.
ATP-independent deactivation of squid rhodopsin.
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鱿鱼视紫红质的 ATP 依赖性失活。
DOI：
10.1017/s0952523800001838
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发表时间：
1992
影响因子：
1.9
通讯作者：
Lisman,JE
中科院分区：
文献类型：
--
作者：
Kahana,A;Robinson,PR;Lewis,LJ;Szuts,EZ;Lisman,JE
以G蛋白与GTPγS的结合作为光激活鱿鱼视紫红质活性的直接测定，研究了光激活鱿鱼视紫红质的体外失活。通过稀释视网膜悬浮液或通过去除可溶性组分来抑制失活。失活可以通过向洗涤过的膜中加入可溶性物质来恢复。这些结果表明，失活是不完全是由于内的构象转变视紫红质本身，但取决于与其他分子的相互作用。研究了磷酸化参与失活的可能性。失活发生在存在和不存在添加的ATP。在存在激酶抑制剂的情况下和加入腺苷三磷酸双磷酸酶后也发生失活，这将残留的ATP水平降低至1μM以下。这些结果表明，光诱导的磷酸化是不需要鱿鱼视紫红质的失活。在这方面，鱿鱼视紫红质的失活不同于脊椎动物视紫红质的失活，脊椎动物视紫红质需要磷酸化。
Deactivation of light-activated squid rhodopsin was studied in vitro using GTPγS binding by G-protein as a direct measure of rhodopsin activity. Deactivation was inhibited by dilution of the retinal suspension or by removal of soluble components. Deactivation could be restored by addition of soluble material to washed membranes. These results indicate that the deactivation is not due entirely to a conformational transition within rhodopsin itself, but depends on the interaction with other molecules. The possibility that phosphorylation is involved in the deactivation was studied. Deactivation occurred in the presence and absence of added ATP. Deactivation also occurred in the presence of kinase inhibitors and after addition of apyrase, which reduced residual ATP levels to below 1μM. These results indicate that light-induced phosphorylation is not required for deactivation of squid rhodopsin. In this regard deactivation of squid rhodopsin is different from that of vertebrate rhodopsin, which requires phosphorylation.