Publication Date:
2008-06-28
Description:
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. Cu(I) oxidation by a photoexcited Re(I)-diimine at position 124 on a histidine(124)-glycine(123)-tryptophan(122)-methionine(121) beta 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shih, Crystal -- Museth, Anna Katrine -- Abrahamsson, Malin -- Blanco-Rodriguez, Ana Maria -- Di Bilio, Angel J -- Sudhamsu, Jawahar -- Crane, Brian R -- Ronayne, Kate L -- Towrie, Mike -- Vlcek, Antonin Jr -- Richards, John H -- Winkler, Jay R -- Gray, Harry B -- DK19038/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 2008 Jun 27;320(5884):1760-2. doi: 10.1126/science.1158241.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18583608" target="_blank"〉PubMed〈/a〉
Keywords:
Azurin/*chemistry
;
Copper/*chemistry
;
Crystallography, X-Ray
;
*Electrons
;
Energy Transfer
;
Kinetics
;
Ligands
;
Models, Chemical
;
Mutant Proteins/chemistry
;
Oxidation-Reduction
;
Phenylalanine/chemistry
;
Pseudomonas aeruginosa/chemistry
;
Rhenium/chemistry
;
Spectrum Analysis
;
Thermodynamics
;
Tryptophan/*chemistry
;
Tyrosine/chemistry
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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