PARENT SESSION
Posters P6A Type II reaction centres: Excited state dynamics and donor side. Abstracts (313-346)

Resonance raman spectroscopy of chlorophyll d and -carotene. Alison Telfer^*,1, Min Chen², Bruno Robert³, Andrew Pascal³, ¹ Imperial College London, London, UK² School of Biological Sciences, Sydney, Australia³ SBFM, Gif-sur-Yvette, France

ABSTRACT- There is great interest in a recently discovered marine cyanobacterium, Acaryochloris marina, which predominantly contains chlorophyll d instead of chlorophyll a. The only difference in structure between chlorophyll d and chlorophyll a is that the vinyl group at position C-3 is replaced by a formyl group. This difference in structure, however, shifts the Qy absorption to a much lower energy so that A. marina absorbs light mainly in the 714-718 nm region, well beyond the absorption of the chlorophyll a containing organisms it lives beneath (see Miyashita et al., Nat. [1996] 383, p 402; Murakami et al., Sci. [2004] 303, p 1633). Resonance Raman (RR) spectroscopy is an excellent method for examining the electronic properties of chlorophyll bound to proteins. Vinyl and formyl groups vibrate at different specific frequencies and so can easily be distinguished. We will present the RR spectra of photosynthetic membranes from A. marina.

KEY WORDS: alpha-carotene, chlorophyll d, Acaryochloris marina, resonance Raman