Changes in structure of the chromophore in the photochemical process of bovine rhodopsin as revealed by FTIR spectroscopy for hydrogen out-of-plane vibrations

• Published in: Biophysical chemistry 1995-09, Vol.56 (1), p.71-78
• Main Authors: Ohkita, Yoshihiro J., Sasaki, Jun, Maeda, Akio, Yoshizawa, Tôru, Groesbeek, Michel, Verdegem, Peter, Lugtenburg, Johan
• Format: Article
• Language: English
• Subjects: Animals; Cattle; Deuterated retinals; Deuterium; FT-IR spectroscopy; Hydrogen; Hydrogen out-of-plane vibration; Lumirhodopsin; Metarhodopsin I; Photochemistry; Protein Conformation; Rhodopsin; Rhodopsin - analogs & derivatives; Rhodopsin - chemistry; Rhodopsin - metabolism; Rod Opsins - chemistry; Rod Opsins - isolation & purification; Rod Opsins - metabolism; Spectroscopy, Fourier Transform Infrared - methods; Vibration
• ISSN: 0301-4622; 1873-4200
• DOI: 10.1016/0301-4622(95)00017-R

The hydrogen out-of-plane bending (HOOP) vibrations were studied in the difference Fourier transform infrared spectra of lumirhodopsin and metarhodopsin I by use of a series of specifically deuterated retinal derivatives of bovine rod outer segments. The 947 cm −1 band of lumirhodopsin and the 950 cm −1 band of metarhodopsin I were assigned to the mode composed of both 11-HOOP and 12-HOOP vibrations. This result suggests that the perturbation near C 12H of the retinal in the earlier intermediate, bathorhodopsin (Palings, van den Berg, Lugtenburg and Mathies, Biochemistry, 28 (1989) 1498–1507), is extinguished in lumirhodopsin and metarhodopsin I. Unphotolyzed rhodopsin and metarhodopsin I exhibited the 14-HOOP bands in the 12-D derivatives at 901 and 886 cm −1, respectively. Lumirhodopsin, however, did not show the 14-HOOP in the 12-D derivatives. The result suggests a change in geometrical alignment of the C 14H bond in lumirhodopsin with respect to the NH bond of the Schiff base.