Vibrational Spectrum of Bathorhodopsin in the Room-Temperature Rhodopsin Photoreaction

摘要

Comparisons of the C=C stretching frequencies at LT and RT reveal a temperature dependence characterized by red shifts of 4 cm~-1 in Rh and 3 cm~-1 in batho, the direction of which is opposite to the blue shifts observed in the visible absorption maxima of Rh (7 nm) and batho (14 nm). This latter observation suggests a stronger interaction of the protein (likely with the counterion Glu-113) with the all-trans-retinal in the batho structure than in the corresponding static batho structure.