Structural Studies on a Photosystem II Reaction-Center Complex Consisting of D-1 and D-2 Polypeptides and Cytochrome <i>b</i>-559 by Resonance Raman Spectroscopy and High-Performance Liquid Chromatography

Abstract

Abstract Resonance Raman spectra of chlorophyll a and β-carotene moieties have been observed from a photosystem II reaction-center complex containing the D-1 and D-2 polypeptides and cytochrome b-559. Examination of the CC double-bond and the keto CO stretching regions of chlorophyll a moiety has indicated that the Mg atom is five-coordinate and the keto CO is hydrogen-bonded. The resonance Raman spectrum of β-carotene moiety has suggested that this carotenoid molecule takes the all-trans form. This suggestion has been supported by an HPLC analysis of the extracted carotenoid.