Tyrosine structural changes detected during the photoactivation of rhodopsin |
| |
Authors: | F DeLange CH Klaassen SE Wallace-Williams PH Bovee-Geurts XM Liu WJ DeGrip KJ Rothschild |
| |
Affiliation: | Department of Biochemistry, Institute of Cellular Signalling, University of Nijmegen, 6500 HB, Nijmegen, The Netherlands. |
| |
Abstract: | We present the first Fourier transform infrared (FTIR) analysis of an isotope-labeled eukaryotic membrane protein. A combination of isotope labeling and FTIR difference spectroscopy was used to investigate the possible involvement of tyrosines in the photoactivation of rhodopsin (Rho). Rho --> MII difference spectra were obtained at 10 degrees C for unlabeled recombinant Rho and isotope-labeled L-[ring-2H4]Tyr-Rho expressed in Spodoptera frugiperda cells grown on a stringent culture medium containing enriched L-[ring-2H4]Tyr and isolated using a His6 tag. A comparison of these difference spectra revealed reproducible changes in bands that correspond to tyrosine and tyrosinate vibrational modes. A similar pattern of tyrosine/tyrosinate bands has also been observed in the bR --> M transition in bacteriorhodopsin, although the sign of the bands is reversed. In bacteriorhodopsin, these bands were assigned to Tyr-185, which along with Pro-186 in the F-helix, may form a hinge that facilitates alpha-helix movement. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|