Determination of chromophore structure and environment in bovine visual pigments with resonance Raman spectroscopy

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7002251

Palings, H A

Resonance Raman spectra of /sup 2/H- and /sup 13/C-labeled visual pigments have been obtained and analyzed. The C-C stretching vibrations of rhodopsin, isorhodopsin, and bathorhodopsin have been assigned, as well as those of the 11-cis and 9-cis retinal protonated Schiff base model compounds. The insensitivity of the C/sub 14/-C/sub 15/ stretch frequency to N-deuteration in all three pigments demonstrates that each contains a trans C=N bond. Comparison of the fingerprint modes of the visual pigments and their model compounds shows that the C/sub 10/-C/sub 11/ and C/sub 14/-C/sub 15/ single bonds are s-trans in all three pigments. This provides evidence against the model of bathorhodopsin proposed by Lui and Asato, which suggests a C/sub 10/-C/sub 11/ s-cis structure. The extreme similarity of the C-C stretch modes of rhodopsin and the 11-cis retinal protonated Schiff base argues against the presence of a negatively charged protein residue near C/sub 13/, proposed to be responsible for the opsin shift of rhodopsin. However, the unusually large shift of the C=N stretch frequency upon N-deuteration in rhodopsin relative to the model compound suggests that the opsin shift mechanism may involve altered Schiff base - counter ion interactions.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 7002251
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
CARBON 13
CARBON ISOTOPES
CATTLE
DEUTERIUM
DOMESTIC ANIMALS
EVEN-ODD NUCLEI
HYDROGEN ISOTOPES
IMINES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MOLECULAR STRUCTURE
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PIGMENTS
PROTEINS
RAMAN SPECTRA
RHODOPSIN
RUMINANTS
SCHIFF BASES
SPECTRA
STABLE ISOTOPES
TRACER TECHNIQUES
VERTEBRATES