Abstract

Halorhodopsin (hR) and bacteriorhodopsin (bR) are retinal proteins in Halobacterium Halobium and both possess the same chromophore (all-trans retinal) and similar protein moieties. In spite of the structural similarity, their biological functions are guite different, hR is a light-driven chloride pump and bR is a proton pump. Photon absorption induces isomerization of the chromophore, followed by ion-pumping. In this paper, subpicosecond time-resolved spectroscopy is applied to hR for the first time and the results are compared with those for bR studied under the same experimental conditions.

© 1992 The Author(s)