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Updated: May 15, 2026

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
Published on: March 13, 2014
Hopping Maps for Photosynthetic Reaction Centers()
Jeffrey J Warren1, Jay R Winkler, Harry B Gray
1Beckman Institute, California Institute of Technology, Mail Code 139-74, Pasadena, CA 91125 USA, Tel: +1 626 395 6500, Fax +1 626 449 4159.
Abstract:
Photosynthetic reaction centers (PRCs) employ multiple-step tunneling (hopping) to separate electrons and holes that ultimately drive the chemistry required for metabolism. We recently developed hopping maps that can be used to interpret the rates and energetics of electron/hole hopping in three-site (donor-intermediate-acceptor) tunneling reactions, including those in PRCs. Here we analyze several key ET reactions in PRCs, including forward ET in the L-branch, and hopping that could involve thermodynamically uphill intermediates in the M-branch, which is ET-inactive in vivo. We also explore charge recombination reactions, which could involve hopping. Our hopping maps support the view that electron flow in PRCs involves strong electronic coupling between cofactors and reorganization energies that are among the lowest in biology (≤ 0.4 eV).
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