Glutamic acid-113 serves as the retinylidene Schiff base counterion in bovine rhodopsin.
- 1 November 1989
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 86 (21), 8309-8313
- https://doi.org/10.1073/pnas.86.21.8309
Abstract
The characteristic wavelength at which a visual pigment absorbs light is regulated by interactions between protein (opsin) and retinylidene Schiff base chromophore. By using site-directed mutagenesis, charged amino acids in bovine rhodopsin transmembrane helix C were systematically replaced. Substitution of glutamic acid-134 or arginine-135 did not affect spectral properties. However, substitution of glutamic acid-122 by glutamine or by aspartic acid formed pigments that were blue-shifted in light absorption (.lambda.max = 480 nm and 475 nm, respectively). While the substitution of glutamic acid-113 by aspartic acid gave a slightly red-shifted pigment (.lambda.max = 505 nm), replacement by glutamine formed a pigment that was strikingly blue-shifted in light absorption (.lambda.max = 380 nm). The 380-nm species existed in a pH-dependent equilibrium with a 490-nm species such that at acidic pH all of the pigment was converted to .lambda.max = 490 nm. We conclude that glutamic acid-113 serves as the retinylidene Schiff base counterion in rhodopsin. We believe that this opsin-chromophore interaction is an example of a general mechanism of color regulation in the visual pigments.This publication has 28 references indexed in Scilit:
- Cysteine residues 110 and 187 are essential for the formation of correct structure in bovine rhodopsin.Proceedings of the National Academy of Sciences, 1988
- A single amino acid substitution in rhodopsin (lysine 248—-leucine) prevents activation of transducin.Journal of Biological Chemistry, 1988
- Deprotonation of the Schiff base of rhodopsin is obligate in the activation of the G protein.Proceedings of the National Academy of Sciences, 1986
- Cloning of the gene and cDNA for mammalian β-adrenergic receptor and homology with rhodopsinNature, 1986
- Two-photon spectroscopy of locked-11-cis-rhodopsin: evidence for a protonated Schiff base in a neutral protein binding site.Proceedings of the National Academy of Sciences, 1985
- Trigger and Amplification Mechanisms in Visual PhototransductionAnnual Review of Biophysics, 1985
- ON THE MECHANISM OF WAVELENGTH REGULATION IN VISUAL PIGMENTSPhotochemistry and Photobiology, 1985
- Isolation, sequence analysis, and intron-exon arrangement of the gene encoding bovine rhodopsinCell, 1983
- Anion-induced wavelength regulation of absorption maxima of Schiff bases of retinalBiochemistry, 1972
- THE MECHANISM OF BLEACHING RHODOPSINAnnals of the New York Academy of Sciences, 1958