Regulation of electron transfer pathways in cytochromes with aromatic amino acids

Abstract

Natural photosynthetic proteins are based upon on chains of reactions that start with sub-nanosecond light energy conversion into energy of electrical charges and followed by multi-step electron transfer (ET). Attempts to develop artificial enzymes for photosynthesis have been relatively futile due to the difficulty of generating sufficiently fast primary charge separation even with the smallest proteins. Here we report our results on attempts to accelerate ET by placing aromatic redox-active amino acids along the putative path of ET for the E39C mutant of PpcA, a 3-heme cytochrome.