Retinal migration during dark reduction of bacteriorhodopsin.
Retinal migration during dark reduction of bacteriorhodopsin.
复制标题
细菌视紫红质暗还原过程中的视网膜迁移。
DOI：
10.1073/pnas.81.8.2303
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发表时间：
1984
影响因子：
11.1
通讯作者：
Stoeckenius,W
中科院分区：
文献类型：
--
作者：
Wolber,PK;Stoeckenius,W
当胰凝乳蛋白酶裂解的细菌视紫红质中的视黄醛席夫碱通过在pH 10下在无光下长时间暴露于10%（wt/vol）氰基硼氢化钠而被还原为仲视黄胺时，发现约45%的视黄醛与Lys-41连接，22%与Lys-40连接，并且剩余部分分散在大的胰凝乳蛋白酶片段上的各个位点上，包括位于Lys-216的生理位点。视网膜结合位点被还原条件破坏或阻断，但细菌视紫红质晶格保持完整。结果表明，在特定条件下，与Lys-40/41的人为连接是可能的。在这些条件下，Lys-40/41的ε-氨基显示出与由Lys-216处的生理连接位点释放的视黄醛形成亚视黄基连接的能力增强，这是由于与正常连接位点的紧密接近以及相对于其他赖氨酸ε-氨基的反应性增加的某种组合。这一结果对两种新发现的视紫红质样蛋白盐视紫红质和慢视紫红质的表征具有重要意义。
When the retinal Schiff base in chymotryptically cleaved bacteriorhodopsin is reduced to a secondary retinylamine by prolonged exposure to 10% (wt/vol) sodium cyanoborohydride, at pH 10, in the absence of light, ≈45% of the retinal is found linked to Lys-41 and 22% to Lys-40, and the remainder is scattered over various sites on the large chymotryptic fragment, including the physiological site at Lys-216. The retinal-binding site is destroyed or blocked by the reduction conditions, but the bacteriorhodopsin lattice remains intact. The results demonstrate that artifactual linkage to Lys-40/41 is possible under special conditions. Under these conditions, the ε-amino groups of Lys-40/41 show an enhanced ability to form retinylidene linkages with the retinal released by the physiological linkage site at Lys-216, due to some combination of close proximity to the normal linkage site, and increased reactivity with respect to other lysine ε-amino groups. The results are of interest for the characterization of the two newly discovered rhodopsin-like proteins, halorhodopsin and slow rhodopsin.