Differential Coupling through Val-344 and Tyr-442 of Trimethylamine Dehydrogenase in Electron Transfer Reactions with Ferricenium Ions and Electron Transferring Flavoprotein†

Biochemistry ◽  
2000 ◽  
Vol 39 (31) ◽  
pp. 9188-9200 ◽  
Author(s):  
Jaswir Basran ◽  
Kamaldeep K. Chohan ◽  
Michael J. Sutcliffe ◽  
Nigel S. Scrutton
Keyword(s):  
Electron Transfer ◽  
Transfer Reactions ◽  
Electron Transfer Reactions ◽  
Trimethylamine Dehydrogenase ◽  
Differential Coupling ◽  
Electron Transferring Flavoprotein

Flavin radicals, conformational sampling and robust design principles in interprotein electron transfer: the trimethylamine dehydrogenase-electron-transferring flavoprotein complex

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Molecular Assembly ◽  
Conformational Sampling ◽  
Trimethylamine Dehydrogenase ◽  
Key Residues ◽  
Electron Transferring Flavoprotein ◽  
Electron Transfer Complex

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.

Quantum effects in adiabatic electrochemical electron-transfer reactions

1997 ◽  
Vol 220 (1-2) ◽  
pp. 95-114 ◽  
Author(s):  
M.T.M. Koper ◽  
J.-H. Mohr ◽  
W. Schmickler
Keyword(s):  
Electron Transfer ◽  
Quantum Effects ◽  
Transfer Reactions ◽  
Electron Transfer Reactions
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