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Inherent chirality of the retinal chromophore in rhodopsin—A nonempirical theoretical analysis of chiroptical data
Author(s) -
Buss Volker
Publication year - 2000
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/1520-636x(2001)13:1<13::aid-chir4>3.0.co;2-3
Subject(s) - chromophore , chemistry , rhodopsin , chirality (physics) , excited state , retinal , protonation , molecular geometry , molecular physics , crystallography , photochemistry , computational chemistry , chemical physics , molecule , atomic physics , physics , organic chemistry , ion , biochemistry , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , quark
CASSCF and GAUSSIAN CIS calculations were performed on ground and excited states of different conformations of 11‐ cis ‐retinal protonated Schiff bases, the chromophore of rhodopsin, in order to study their chiroptical properties and attempt a correlation between absolute conformation and CD‐spectral data. Geometries were taken from molecular models, from published rhodopsin models, and from retinal conformations obtained from molecular dynamics with geometry restraints. In all the cases studied we find that a positive sense of twist about the C12‐C13 bond correlates with a calculated positive CD of the long wavelength absorption band; the twist of the C6‐C7 bond modulates this primary contribution of the C12‐C13 bond. The correlation of the β‐band with structural features is not straightforward. Calculations on bathorhodopsin lend support to the idea that this intermediate is a highly twisted all‐ trans ‐conformation. Chirality 13:13–23, 2001. © 2000 Wiley‐Liss, Inc.