Submolecular Gates Self-Assemble for Hot-Electron Transfer in Proteins.

Autor:	Filip-Granit N; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., Goldberg E; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., Samish I; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., Ashur I; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., van der Boom ME; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., Cohen H; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel., Scherz A; Department of Plant and Environmental Sciences, ‡Department of Organic Chemistry, and §Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 7610001, Israel.
Jazyk:	angličtina
Zdroj:	The journal of physical chemistry. B [J Phys Chem B] 2017 Jul 27; Vol. 121 (29), pp. 6981-6988. Date of Electronic Publication: 2017 Jul 12.
DOI:	10.1021/acs.jpcb.7b00432
Abstrakt:	Redox reactions play key roles in fundamental biological processes. The related spatial organization of donors and acceptors is assumed to undergo evolutionary optimization facilitating charge mobilization within the relevant biological context. Experimental information from submolecular functional sites is needed to understand the organization strategies and driving forces involved in the self-development of structure-function relationships. Here we exploit chemically resolved electrical measurements (CREM) to probe the atom-specific electrostatic potentials (ESPs) in artificial arrays of bacteriochlorophyll (BChl) derivatives that provide model systems for photoexcited (hot) electron donation and withdrawal. On the basis of computations we show that native BChl's in the photosynthetic reaction center (RC) self-assemble at their ground-state as aligned gates for functional charge transfer. The combined computational and experimental results further reveal how site-specific polarizability perpendicular to the molecular plane enhances the hot-electron transport. Maximal transport efficiency is predicted for a specific, ∼5 Å, distance above the center of the metalized BChl, which is in remarkably close agreement with the distance and mutual orientation of corresponding native cofactors. These findings provide new metrics and guidelines for analysis of biological redox centers and for designing charge mobilizing machines such as artificial photosynthesis.
Databáze:	MEDLINE
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