Similarity and difference in the photochemistry of type I and II rhodopsins

Abstract

The diversity of retinal-containing proteins in nature is extremely large. The fundamental similarity of the structure and photochemical properties unites them into one family. However, there is still a debate about the origin of retinal-containing proteins: divergent or convergent evolution? In this review, based on the results of our own and literature data, a comparative analysis of the similarities and differences in the photoconversion of rhodopsin types I and II is carried out. The results of experimental studies of direct and reverse photoreactions of rhodopsin types I (bacteriorhodopsin) and II (visual rhodopsin) in the femto- and picosecond time interval, photo-reversible reaction of rhodopsin type II (octopus rhodopsin), photovoltaic reactions of rhodopsin types I and II, as well as quantum chemical calculations of forward photoreactions of bacteriorhodopsin and visual rhodopsin are presented. The question of the probable convergent evolution of rhodopsin types I and II is discussed.