sup 13 C magic-angle spinning NMR studies of bathorhodopsin, the primary photoproduct of rhodopsin

Journal Article · Tue Jul 30 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00244a007· OSTI ID:5077272

Smith, S O ^[1]; Courtin, J; de Groot, H; Gebhard, R; Lugtenburg, J ^[2]

---

1. Yale Univ., New Haven, CT (United States)
2. Rijksuniversiteit te Leiden (Netherlands)

Magic-angle spinning NMR spectra have been obtained of the bathorhodopsin photointermediate trapped at low temperature (<130 K) by using isorhodopsin samples regenerated with retinal specifically {sup 13}C-labeled at positions 8, 10, 11, 12, 13, 14, and 15. Comparison of the chemical shifts of the bathorhodpsin resonances with those of an all-trans-retinal protonated Schiff base (PSB) chloride salt show the largest difference (6.2 ppm) at position 13 of the protein-bound retinal. Small differences in chemical shift between bathorhodopsin and the all-trans PSB model compound are also observed at positions 10, 11, and 12. The effects are almost equal in magnitude to those previously observed in rhodopsin and isorhodopsin. Consequently, the energy stored in the primary photoproduct bathorhodopsin does not give rise to any substantial change in the average electron density at the labeled positions. The data indicate that the electron and structural properties of the protein environment are similar to those in rhodopsin and isorhodopsin. In particular, a previously proposed perturbation near position 13 of the retinal appears not to change its position significantly with respect to the chromophore upon isomerization. The data effectively exclude charge separation between the chromophore and a protein residue as the main mechanism for energy storage in the primary photoproduct and argue that the light energy is stored in the form of distortions of the bathorhodopsin chromophore.

• OSTI ID: 5077272
• Journal Information: Biochemistry; (United States), Vol. 30:30; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
RHODOPSIN
NUCLEAR MAGNETIC RESONANCE
CARBON 13
CATTLE
CHEMICAL SHIFT
LOW TEMPERATURE
PHOTOCHEMICAL REACTIONS
RETINA
ANIMALS
BODY
BODY AREAS
CARBON ISOTOPES
CHEMICAL REACTIONS
DOMESTIC ANIMALS
EVEN-ODD NUCLEI
EYES
FACE
HEAD
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MAMMALS
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PIGMENTS
PROTEINS
RESONANCE
RUMINANTS
SENSE ORGANS
STABLE ISOTOPES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics