Through-space electrostatic effects in electronic spectra. Experimental evidence for the external point-charge model of visual pigments

1979 ◽  
Vol 101 (23) ◽  
pp. 7086-7088 ◽  
Author(s):  
Mordechai Sheves ◽  
Koji Nakanishi ◽  
Barry Honig
Keyword(s):  
Experimental Evidence ◽  
Electronic Spectra ◽  
Point Charge ◽  
Visual Pigments ◽  
Electrostatic Effects ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model

ChemInform Abstract: AN EXTERNAL POINT-CHARGE MODEL FOR WAVELENGTH REGULATION IN VISUAL PIGMENTS

1980 ◽  
Vol 11 (7) ◽  
Author(s):  
B. HONIG ◽  
U. DINUR ◽  
K. NAKANISHI ◽  
V. BALOGH-NAIR ◽  
M. A. GAWINOWICZ ◽  
...  
Keyword(s):  
Point Charge ◽  
Visual Pigments ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model ◽  
Wavelength Regulation

An external point-charge model for wavelength regulation in visual pigments

1979 ◽  
Vol 101 (23) ◽  
pp. 7084-7086 ◽  
Author(s):  
Barry Honig ◽  
Uri Dinur ◽  
Koji Nakanishi ◽  
Valeria Balogh-Nair ◽  
Mary Ann Gawinowicz ◽  
...  
Keyword(s):  
Point Charge ◽  
Visual Pigments ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model ◽  
Wavelength Regulation

Bacteriorhodopsin analogue from anthryl chromophores

1990 ◽  
Vol 68 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Anil K. Singh ◽  
Mita Roy
Keyword(s):  
Absorption Band ◽  
Dark Adaptation ◽  
Point Charge ◽  
Spectrophotometric Analysis ◽  
Reaction Centre ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model ◽  
Nuclear Magnetic Resonance Spectra ◽  
Opsin Shift

Preparation and properties of the bacteriorhodopsin (bR) analogue having the 3,7-dimethyl-9-(9-anthryl)-2E,4E,6E,8E-nonatetraenal (12) chromophore is described. Synthesis of the chromophore has been achieved by successive introduction of C5 units to 9-anthraldehyde (3) via the Horner reaction. The all-trans chromophore has been characterized by its ultraviolet–visible and 1H nuclear magnetic resonance spectra. Incubation of 12 with bacterioopsin suspension (prepared by photobleaching of bR isolated from Halobacteriumhalobium) at ambient temperature in the dark gave the new bR analogue 15, which showed an absorption band at 545 nm, and an opsin shift of 5575 cm−1. The new pigment is stable to hydroxylamine in the dark. It showed light–dark adaptation with the light-adapted form absorbing at a slightly red-shifted value of 550 nm. All-trans-retinal did not replace the anthryl chromophore in competitive bindings. Photolysis of the bR analogue 15, followed by difference spectrophotometric analysis, indicated formation of a photoproduct with an absorption band near 400 nm. The results are discussed in terms of the stereoelectronic requirements of the bR reaction centre. Keywords: bacteriorhodopsin (bR), retinal analogue, reconstitution, opsin shift (OS), external point charge model (EPC).

Bacteriorhodopsins containing cyanine dye chromophores. Support for the external point-charge model

1983 ◽  
Vol 105 (3) ◽  
pp. 646-648 ◽  
Author(s):  
Fadila Derguini ◽  
Charles G. Caldwell ◽  
Michael G. Motto ◽  
Valeria Balogh-Nair ◽  
Koji Nakanishi
Keyword(s):  
Point Charge ◽  
Cyanine Dye ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model

DOUBLE POINT CHARGE MODEL FOR VISUAL PIGMENTS; EVIDENCE FROM DIHYDRORHODOPSINS

1979 ◽  
Vol 29 (4) ◽  
pp. 657-660 ◽  
Author(s):  
K. Nakanishi ◽  
V. Balogh-Nair ◽  
M. A. Gawinowicz ◽  
M. Arnaboldi ◽  
M. Motto ◽  
...  
Keyword(s):  
Point Charge ◽  
Double Point ◽  
Visual Pigments ◽  
Point Charge Model ◽  
Charge Model

ChemInform Abstract: BACTERIORHODOPSINS CONTAINING CYANINE DYE CHROMOPHORES. SUPPORT FOR THE EXTERNAL POINT-CHARGE MODEL

1983 ◽  
Vol 14 (22) ◽  
Author(s):  
F. DERGUINI ◽  
C. G. CALDWELL ◽  
M. G. MOTTO ◽  
V. BALOGH-NAIR ◽  
K. NAKANISHI
Keyword(s):  
Point Charge ◽  
Cyanine Dye ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model

ChemInform Abstract: AN EXTERNAL POINT-CHARGE MODEL FOR BACTERIORHODOPSIN TO ACCOUNT FOR ITS PURPLE COLOR

1981 ◽  
Vol 12 (14) ◽  
Author(s):  
K. NAKANISHI ◽  
V. BALOGH-NAIR ◽  
M. ARNABOLDI ◽  
K. TSUJIMOTO ◽  
B. HONIG
Keyword(s):  
Point Charge ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model ◽  
Purple Color

An external point-charge model for bacteriorhodopsin to account for its purple color

1980 ◽  
Vol 102 (27) ◽  
pp. 7945-7947 ◽  
Author(s):  
Koji Nakanishi ◽  
Valeria Balogh-Nair ◽  
Maria Arnaboldi ◽  
Kazuo Tsujimoto ◽  
Barry Honig
Keyword(s):  
Point Charge ◽  
Point Charge Model ◽  
External Point ◽  
Charge Model ◽  
Purple Color

Effects of solvents on a model of rhodopsin consisting of a conjugated imine and substituted acetic acids

1984 ◽  
Vol 62 (8) ◽  
pp. 1459-1464 ◽  
Author(s):  
Martine Bissonnette ◽  
Hoa Le Thanh ◽  
Daniel Vocelle
Keyword(s):  
Schiff Base ◽  
Experimental Evidence ◽  
Point Charge ◽  
Model System ◽  
Visual Pigments ◽  
The State ◽  
Nmr Data ◽  
Acidic Proton ◽  
External Point ◽  
Acetic Acids

A model system of rhodopsin consisting of a dienylidene Schiff base and different halogeno acids has been studied in two solvents, chloroform and methanol, by uv and 400-MHz nmr spectroscopies. The uv results indicate that in chloroform, a nonpolar solvent, monohalogenoacetic acids can protonate the Schiff base only partially, while nmr data show that the aldimine hydrogen is slightly affected by acids and that the acidic proton is moving rapidly between the donor and the acceptor. In methanol, data indicate a leveling effect. In relation with rhodopsin, our results imply that, depending on the environment surrounding the chromophore, the state of protonation of the Schiff base could be strongly affected. Finally, our model shows experimental evidence that Nakanishi's external point charge could be operating in visual pigments.

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