Tryptophan-accelerated electron flow through proteins
2008 (English)In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 320, no 5884, 1760-1762 p.Article in journal (Refereed) Published
Energy flow in biological structures often requires submillisecond charge transport over long molecular distances. Kinetics modeling suggests that charge-transfer rates can be greatly enhanced by multistep electron tunneling in which redox-active amino acid side chains act as intermediate donors or acceptors. We report transient optical and infrared spectroscopic experiments that quantify the extent to which an intervening tryptophan residue can facilitate electron transfer between distant metal redox centers in a mutant Pseudomonas aeruginosa azurin. CuI oxidation by a photoexcited ReI-diimine at position 124 on a histidine(124)-glycine(123)-tryptophan(122)-methionine(121) β strand occurs in a few nanoseconds, fully two orders of magnitude faster than documented for single-step electron tunneling at a 19 angstrom donor-acceptor distance.
Place, publisher, year, edition, pages
2008. Vol. 320, no 5884, 1760-1762 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-85312DOI: 10.1126/science.1158241OAI: oai:DiVA.org:liu-85312DiVA: diva2:568077