Femtosecond dynamics of short-range protein electron transfer in flavodoxin

Ting Fang He, Lijun Guo, Xunmin Guo, Chih Wei Chang, Lijuan Wang, Dongping Zhong

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Intraprotein electron transfer (ET) in flavoproteins is important for understanding the correlation of their redox, configuration, and reactivity at the active site. Here, we used oxidized flavodoxin as a model system and report our complete characterization of a photoinduced redox cycle from the initial charge separation in 135-340 fs to subsequent charge recombination in 0.95-1.6 ps and to the final cooling relaxation of the product(s) in 2.5-4.3 ps. With 11 mutations at the active site, we observed that these ultrafast ET dynamics, much faster than active-site relaxation, mainly depend on the reduction potentials of the electron donors with minor changes caused by mutations, reflecting a highly localized ET reaction between the stacked donor and acceptor at a van der Waals distance and leading to a gas-phase type of bimolecular ET reaction confined in the active-site nanospace. Significantly, these ultrafast ET reactions ensure our direct observation of vibrationally excited reaction product(s), suggesting that the back ET barrier is effectively reduced because of the decrease in the total free energy in the Marcus inverted region, leading to the accelerated charge recombination. Such vibrationally coupled charge recombination should be a general feature of flavoproteins with similar configurations and interactions between the cofactor flavin and neighboring aromatic residues.

Original languageEnglish
Pages (from-to)9120-9128
Number of pages9
JournalBiochemistry
Volume52
Issue number51
DOIs
Publication statusPublished - 2013 Dec 23

Fingerprint

Flavodoxin
Electrons
Catalytic Domain
Genetic Recombination
Proteins
Flavoproteins
Oxidation-Reduction
Electron-Transferring Flavoproteins
Mutation
Reaction products
Free energy
Gases
Observation
Cooling

All Science Journal Classification (ASJC) codes

  • Biochemistry

Cite this

He, Ting Fang ; Guo, Lijun ; Guo, Xunmin ; Chang, Chih Wei ; Wang, Lijuan ; Zhong, Dongping. / Femtosecond dynamics of short-range protein electron transfer in flavodoxin. In: Biochemistry. 2013 ; Vol. 52, No. 51. pp. 9120-9128.
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Femtosecond dynamics of short-range protein electron transfer in flavodoxin. / He, Ting Fang; Guo, Lijun; Guo, Xunmin; Chang, Chih Wei; Wang, Lijuan; Zhong, Dongping.

In: Biochemistry, Vol. 52, No. 51, 23.12.2013, p. 9120-9128.

Research output: Contribution to journalArticle

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AU - Zhong, Dongping

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