Spudich J L, McCain D A, Nakanishi K, Okabe M, Shimizu N, Rodman H, Honig B, Bogomolni R A
Biophys J. 1986 Feb;49(2):479-83. doi: 10.1016/S0006-3495(86)83657-8.
Retinal analogues with altered conjugated double bond systems or altered stereochemistry were incorporated into the phototaxis receptor sensory rhodopsin (SR) and the light-driven proton pump bacteriorhodopsin (BR) from Halobacterium halobium. Wavelength shifts in absorption ("opsin shifts") due to analogue interaction with the protein microenvironment demonstrate that the same overall electrostatic and steric properties of the retinal binding-site structures exist in both proteins despite their different functions. pi-Electron calculations from the opsin shifts lead to a new description of protein charge distribution that applies to the binding sites of both SR and BR. The new data extends the previously proposed external point charge model for BR to include an ion-pair protein/chromophore interaction near the beta-ionone moiety. The new data modifies the previously proposed external point-charge model, the derivation of which involved an experimentally erroneous opsin shift for one of the BR analogues.
将具有改变的共轭双键系统或改变的立体化学的视网膜类似物掺入来自嗜盐嗜盐菌的趋光性受体感官视紫红质（SR）和光驱动质子泵细菌视紫红质（BR）中。由于类似物与蛋白质微环境的相互作用而导致的吸收波长变化（“视蛋白位移”）表明，尽管这两种蛋白质功能不同，但它们的视网膜结合位点结构具有相同的整体静电和空间性质。根据视蛋白位移进行的π电子计算得出了一种适用于SR和BR结合位点的蛋白质电荷分布新描述。新数据扩展了先前提出的BR外部点电荷模型，以包括在β-紫罗兰酮部分附近的离子对蛋白质/发色团相互作用。新数据修改了先前提出的外部点电荷模型，该模型的推导涉及BR类似物之一的实验错误视蛋白位移。
