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The nature of aqueous tunneling pathways between electron-transfer proteins.

ABSTRACT: Structured water molecules near redox cofactors were found recently to accelerate electron-transfer (ET) kinetics in several systems. Theoretical study of interprotein electron transfer across an aqueous interface reveals three distinctive electronic coupling mechanisms that we describe here: (i) a protein-mediated regime when the two proteins are in van der Waals contact; (ii) a structured water-mediated regime featuring anomalously weak distance decay at relatively close protein-protein contact distances; and (iii) a bulk water-mediated regime at large distances. Our analysis explains a range of otherwise puzzling biological ET kinetic data and provides a framework for including explicit water-mediated tunneling effects on ET kinetics.

SUBMITTER: Lin J

PROVIDER: S-EPMC3613566 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature

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The nature of aqueous tunneling pathways between electron-transfer proteins.

Lin Jianping J Balabin Ilya A IA Beratan David N DN

Science (New York, N.Y.) 20051101 5752

Structured water molecules near redox cofactors were found recently to accelerate electron-transfer (ET) kinetics in several systems. Theoretical study of interprotein electron transfer across an aqueous interface reveals three distinctive electronic coupling mechanisms that we describe here: (i) a protein-mediated regime when the two proteins are in van der Waals contact; (ii) a structured water-mediated regime featuring anomalously weak distance decay at relatively close protein-protein contac ...[more]

PMID: 16311331

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