Ftir study of the protonation of a retinyl schiff base in chloroform/methanol mixtures

Fourter transform infrared spectra of a retinyl Schiff base in the presence of one of a series of acids were recorded in solvents containing chloroform and methanol in different proportions. The spectra show that methanol makes it possible for weak acids to achieve complete protonation of the Schiff base. This leads to the hypothesss that water or other OH containing molecules could play a role in bringing about complete protonation of the Schiff base chromophore in rhodopsins.

[1]  S. Badilescu,et al.  THE PROTONATION OF A RETINYL SCHIFF BASE , 1989, Photochemistry and photobiology.

[2]  D. Vocelle,et al.  The Problem of Protonation in Rhodopsin and Model Schiff Bases , 1989 .

[3]  D. Vocelle,et al.  THE EFFECT OF ACIDS ON THE INFRARED SPECTRA OF SCHIFF BASES—II. IMINES CONTAINING THE C=C‐C=N AND C=C‐C=C‐C=N UNITS , 1987 .

[4]  D. Vocelle,et al.  Effect of acids on the infrared spectra of the Schiff base of trans-retinal , 1987 .

[5]  D. Vocelle,et al.  The photochemical event in rhodopsins , 1986 .

[6]  D. Vocelle,et al.  THE EFFECT OF ACIDS ON THE INFRARED SPECTRA OF SCHIFF BASES—I. NON‐CONJUGATED IMINES , 1986 .

[7]  M. Stockburger,et al.  Structure of bacteriorhodopsin in the acidified membrane and at high ionic strength: resonance Raman study , 1985 .

[8]  P. Hildebrandt,et al.  Role of water in bacteriorhodopsin's chromophore: resonance Raman study , 1984 .

[9]  B. Honig.  Chapter 20 Photochemical Charge Separation and Active Transport in the Purple Membrane , 1982 .

[10]  W. Stoeckenius,et al.  Bacteriorhodopsin and related pigments of halobacteria. , 1982, Annual review of biochemistry.

[11]  C. Rafferty,et al.  THE INVOLVEMENT OF WATER AT THE RETINAL BINDING SITE IN RHODOPSIN AND EARLY LIGHT‐INDUCED INTRAMOLECULAR PROTON TRANSFER , 1981, Photochemistry and photobiology.

[12]  R. Birge,et al.  Photophysics of light transduction in rhodopsin and bacteriorhodopsin. , 1981, Annual review of biophysics and bioengineering.

[13]  P. E. Blatz,et al.  Anion-induced wavelength regulation of absorption maxima of Schiff bases of retinal. , 1972, Biochemistry.