X-Ray Diffraction Pattern from Internal Structure of Bovine Rhodopsin

Abstract

Pure bovine rhodopsin pellets were prepared by removal of cholie acid from rhodopsincholie acid complex, and X-ray diffraction patterns from the internal structure of rhodopsin were obtained for the first time using wet and dry pellet samples. The peaks at around 10 and 4.3 Å spacings observed for both samples can be attributed to α-helices in rhodopsin molecule, providing direct evidence of the helical structure of rhodopsin. A shoulder peak at around 34 Å spacing was also observed for the dry pellet, which can be explained by the first-neighbor distance between rhodopsin molecules in the sample.