Assignment of fingerprint vibrations in the resonance Raman spectra of rhodopsin, isorhodopsin, and bathorhodopsin: implications for chromophore structure and environment

Journal Article · Tue May 05 00:00:00 EDT 1987 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00383a021· OSTI ID:5850962

Palings, I; Pardoen, J A; van den Berg, E; Winkel, C; Lugtenburg, J; Mathies, R A

/sup 13/C- and /sup 2/H-labeled retinal derivatives have been used to assign normal modes in the 1100-1300-cm/sup -1/ fingerprint region of the resonance Raman spectra of rhodopsin, isorhodopsin, and bathorhodopsin. On the basis of the /sup 13/C shifts, C/sub 8/-C/sub 9/ stretching character is assigned at 1217 cm/sup -1/ in rhodopsin, at 1206 cm/sup -1/ in isorhodopsin, and at 1214 cm/sup -1/ in bathorhodopsin. C/sub 10/-C/sub 11/ stretching character is localized at 1098 cm/sup -1/ in rhodopsin, at 1154 cm/sup -1/ in isorhodopsin, and at 1166 cm/sup -1/ in bathorhodopsin. C/sub 14/-C/sub 15/ stretching character is found at 1190 cm/sup -1/ in rhodopsin, at 1206 cm/sup -1/ in isorhodopsin, and at 1210 cm/sup -1/ in bathorhodopsin. C/sub 12/-C/sub 13/ stretching character is much more delocalized, but the characteristic coupling with the C/sup 14/H rock allows the authors to assign the C/sup 12/-C/sup 13/ stretch at approx.1240 cm/sup -1/ in rhodopsin, isorhodopsin, and bathorhodopsin. The insensitivity of the C/sub 14/-C/sub 15/ stretching mode to N-deuteriation in all three pigments demonstrates that each contains a trans (anti) protonated Schiff base bond. The relatively high frequency of the C/sub 10/-C/sub 11/ mode of bathorhodopsin demonstrates that bathorhodopsin is s-trans about the C/sub 10/-C/sub 11/ single bond. This provides strong evidence against the model of bathorhodopsin proposed by Liu and Asato, which suggests a C/sub 10/-C/sub 11/ s-cis structure. Comparison of the fingerprint modes of rhodopsin with those of the 11-cis-retinal protonated Schiff base in methanol shows that the frequencies of the C-C stretching modes are largely unperturbed by protein binding. The implications of these observations for the mechanism of wavelength regulation in visual pigments and energy storage in bathorhodopsin are discussed.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5850962
• Journal Information: Biochemistry; (United States), Vol. 26:9
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
PIGMENTS
PHOTOCHEMISTRY
RAMAN SPECTRA
RHODOPSIN
DERIVATIZATION
CARBON 13
CHEMICAL BONDS
CHEMICAL SHIFT
DEUTERIUM COMPOUNDS
MOLECULAR STRUCTURE
RETINA
SCHIFF BASES
VIBRATIONAL STATES
BODY
BODY AREAS
CARBON ISOTOPES
CHEMICAL REACTIONS
CHEMISTRY
ENERGY LEVELS
EVEN-ODD NUCLEI
EXCITED STATES
EYES
FACE
HEAD
HYDROGEN COMPOUNDS
IMINES
ISOTOPES
LIGHT NUCLEI
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PROTEINS
SENSE ORGANS
SPECTRA
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics