Abstract
The primary charge separation in photosynthetic reaction centers (RC) is carried out by an array of (bacterio)chlorophylls arranged in close proximity. The recent x-ray structures of the RC complexes from Rhodopseudomonas viridis 1–3 and Rhodobacter sphaeroides 4,5 reveal two possible electron pathways for purple bacteria, only one of which is active.6 In order to determine the environmental factors most likely to affect the direction of electron flow in the nascent charge separation, we have calculated the effects of hydrogen bonding and chemical modification (enolization) by nearby residues upon the optical spectra, reduction potentials, unpaired spin density distributions and charge densities of bacterio-chlorophylls (BChl) and -pheophytins (BPh).
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Hanson, L.K., Thompson, M.A., Zerner, M.C., Fajer, J. (1988). Theoretical Models of Electrochromic and Environmental Effects on Bacterio-Chlorophylls and -Pheophytins in Reaction Centers. In: Breton, J., Verméglio, A. (eds) The Photosynthetic Bacterial Reaction Center. NATO ASI Series, vol 149. Springer, Boston, MA. https://doi.org/10.1007/978-1-4899-0815-5_36
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