Yeagle P L, Alderfer J L, Albert A D
Department of Biochemistry, School of Medicine and Biomedical Sciences, University of Buffalo, New York 14214, USA.
Biochemistry. 1997 Aug 12;36(32):9649-54. doi: 10.1021/bi970908a.
Rhodopsin is a G protein receptor from a many-membered family of membrane receptors. No high-resolution structure exists for any member of this family due to the insolubility of membrane proteins and the difficulty in crystallizing membrane proteins. Two new approaches to the structure of rhodopsin are described that circumvent these limitations: (1) individual solution structures of the four cytoplasmic domains of rhodopsin are fitted with the transmembrane domain; (2) the solution structure of a complex of the four cytoplasmic domains is determined from nuclear magnetic resonance data. The two structures are similar. To test the validity of these structures, specific site-to-site distances measured on intact membrane-bound rhodopsin are compared to the same distances on the structures reported here. Excellent agreement is obtained. Furthermore, the agreement is obtained with distances measured on the activated form of teh receptor and not with distances on the dark-adapted form of rhodopsin. This approach may prove to have general applicability for the determination of the structure for membrane proteins.
视紫红质是膜受体众多成员家族中的一种G蛋白受体。由于膜蛋白的不溶性以及膜蛋白结晶的困难，该家族的任何成员都不存在高分辨率结构。本文描述了两种解决视紫红质结构问题的新方法，它们克服了这些限制：（1）视紫红质四个胞质结构域的单个溶液结构与跨膜结构域相拟合；（2）由核磁共振数据确定四个胞质结构域复合物的溶液结构。这两种结构相似。为了检验这些结构的有效性，将完整膜结合视紫红质上测量的特定位点间距离与本文报道的结构上的相同距离进行比较。结果得到了很好的一致性。此外，这种一致性是在受体的激活形式上测量的距离，而不是在视紫红质的暗适应形式上测量的距离。这种方法可能被证明对确定膜蛋白的结构具有普遍适用性。
