Chromophore Heterogeneity and Photoconversion in Phytoehrome Crystals and Solution Studied by Resonance Raman Spectroscopy

摘要

Phytochromes constitute a family of sensory photoreceptors ubiquitous in plants,bacteria,and fungi.The light-sensing cofactor,a methine-bridged tetrapyrrole,is covalently bound to the apoprotein through a thioether linkage(Figure 1).Upon light absorption in the parent state Pr,the chromophore undergoes a Z->E double-bond isomerization of the methine bridge between the rings C and D,followed by thermal relaxation steps,thereby coupling structural changes in the chromophore and protein.