Shuster T A, Nagy A K, Farber D B
Jules Stein Eye Institute, University of California, Los Angeles 90024.
Exp Eye Res. 1988 May;46(5):647-55. doi: 10.1016/s0014-4835(88)80053-8.
The rod photoreceptor outer segment maintains a remarkable morphology. Two of the proteins which have been implicated in the maintenance of this structure are the 240 kDa spectrin-like protein, and the 220 kDa glycoprotein often referred to as the rim protein. We have probed rat rod outer segment proteins with light-activated (azido-labeled) radioactive nucleotides and found a nucleotide binding site(s) on the rim protein which has a preference for guanine nucleotides. Binding to this site is stimulated by the divalent cations zinc, manganese and magnesium, but not calcium. This site is under investigation and may play a role in stabilizing protein structure.
视杆光感受器外段保持着显著的形态。与维持这种结构有关的两种蛋白质是240 kDa的血影蛋白样蛋白和通常被称为边缘蛋白的220 kDa糖蛋白。我们用光激活（叠氮标记）的放射性核苷酸探测大鼠视杆外段蛋白，在边缘蛋白上发现了一个对鸟嘌呤核苷酸有偏好的核苷酸结合位点。锌、锰和镁等二价阳离子可刺激与该位点的结合，但钙不能。该位点正在研究中，可能在稳定蛋白质结构中发挥作用。
