Crystallographic characterization by X-ray diffraction of the M-intermediate from the photo-cycle of bacteriorhodopsin at room temperature.
The structure of the M-intermediate appearing in the photo-cycle of bacteriorhodopsin was studied with X-ray diffraction techniques at room temperature. The lifetime of the M-intermediate was prolonged by treatment with an arginine solution at alkaline pH (Nakasako et al., FEBS Lett. 254, 211-214). The diffraction profile of membranes which had accumulated the M-intermediate had small but significant differences in the intensities of Bragg reflections and the lattice constant in comparison with that of membranes having trans-bacteriorhodopsin. Diffraction intensities were carefully evaluated and the structural changes during the formation of the intermediate were evaluated with difference Fourier analysis. We could find structural changes around helices G and B.
Nakasako
M
M
Department of Physics, Faculty of Science, Tohoku University, Miyagi, Japan.
Kataoka
M
M
Amemiya
Y
Y
Tokunaga
F
F
D001436:Bacteriorhodopsins / Q000737:chemistry*; D003461:Crystallography; D004583:Electrons; D019617:Halobacterium salinarum / Q000737:chemistry; D010777:Photochemistry; D013696:Temperature; D014961:X-Ray Diffraction
D001436:Bacteriorhodopsins