Issue 5, 2018

In situ” observation of the role of chloride ion binding to monkey green sensitive visual pigment by ATR-FTIR spectroscopy

Abstract

Long-wavelength-sensitive (LWS) pigment possesses a chloride binding site in its protein moiety. The binding of chloride alters the absorption spectra of LWS; this is known as the chloride effect. Although the two amino acid substitutions of His197 and Lys200 influence the chloride effect, the molecular mechanism of chloride binding, which underlies the spectral tuning, has yet to be clarified. In this study, we applied ATR-FTIR spectroscopy to monkey green (MG) pigment to gain structural information of the chloride binding site. The results suggest that chloride binding stabilizes the β-sheet structure on the extracellular side loop with perturbation of the retinal polyene chain, promotes a hydrogen bonding exchange with the hydroxyl group of Tyr, and alters the protonation state of carboxylate. Combining with the results of the binding analyses of various anions (Br, I and NO3), our findings suggest that the anion binding pocket is organized for only Cl (or Br) to stabilize conformation around the retinal chromophore, which is functionally relevant with absorbing long wavelength light.

Graphical abstract: “In situ” observation of the role of chloride ion binding to monkey green sensitive visual pigment by ATR-FTIR spectroscopy

Supplementary files

Article information

Article type
Paper
Submitted
27 Қаз. 2017
Accepted
19 Жел. 2017
First published
19 Жел. 2017

Phys. Chem. Chem. Phys., 2018,20, 3381-3387

In situ” observation of the role of chloride ion binding to monkey green sensitive visual pigment by ATR-FTIR spectroscopy

K. Katayama, Y. Furutani, M. Iwaki, T. Fukuda, H. Imai and H. Kandori, Phys. Chem. Chem. Phys., 2018, 20, 3381 DOI: 10.1039/C7CP07277E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements