Tyrosine structural changes detected during the photoactivation of rhodopsin.
J Biol Chem
; 273(37): 23735-9, 1998 Sep 11.
Article
em 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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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Conformação Proteica
/
Rodopsina
/
Tirosina
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Holanda