Circular dichroism and cross-linking studies of bacteriorhodopsin mutants.
Amino Acids
; 30(1): 17-23, 2006 Feb.
Article
en En
| MEDLINE
| ID: mdl-16477391
ABSTRACT
Circular dichroism (CD) spectroscopy was employed for native (wild type, WT) bacteriorhodopsin (bR) and several mutant derivatives R134K, R134H, R82Q, S35C, L66C, and R134C/E194C. Comparative analysis of the CD spectra in visible range shows that only R134C/E194C exhibits biphasic CD, typical for native bR, the other mutants demonstrate CD spectra with significantly smaller or absent negative band. Since the biphasic CD is a feature of hexagonal lattice structure composed by bR trimers in the purple membrane, these mutants and WT were examined by cross-linking studies, which confirmed the same trend towards trimeric organization. Therefore, a single amino acid substitution may lead to drastically different CD spectra without disruption of bR trimeric organization. Thus, although disruption of bR trimeric crystalline lattice structure (e.g., solubilization with detergents) directly results in the disappearance of characteristic bilobe in visible CD, the lack of the bilobe in the CD alone does not predict the absence of trimers.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bacteriorodopsinas
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Amino Acids
Asunto de la revista:
BIOQUIMICA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos