Tyrosine structural changes detected during the photoactivation of rhodopsin.
J Biol Chem
; 273(37): 23735-9, 1998 Sep 11.
Article
in En
| MEDLINE
| ID: mdl-9726981
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.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Conformation
/
Rhodopsin
/
Tyrosine
Limits:
Animals
Language:
En
Journal:
J Biol Chem
Year:
1998
Document type:
Article