Trimethylamine dehydrogenase electron transfer

Stopped-flow studies on electron transfer between two-electron reduced trimethylamine dehydrogenase and ETF are complicated by internal electron-transfer steps between the flavin and iron—sulfur center of trimethylamine dehydrogenase " therefore, a modified enzyme in which the FMN prosthetic group was derivatized by phenylhydrazine, making it redox inert, was used." " This modified enzyme, reduced by one electron by dithionite, reacts with oxidized FTF" at 5 °C and pH 7.0 with a bimolecular rate constant of... 

R. Hille and R.F. Anderson, Coupled electron/proton transfer in complex flavoproteins — solvent kinetic isotope effect studies of electron transfer in xanthine oxidase and trimethylamine dehydrogenase. J. Biol. Chem. 276, 31193-31201 (2001). 

Rohlfs, R. J., and Hille, R., 1991, Intramolecular electron transfer in trimethylamine dehydrogenase from bacterium W-3A1. J. Biol. Chem. 266 152441115252. 

Falzon, L., and Davidson V. L., 1996, Intramolecular electron transfer in trimethylamine dehydrogenase A thermodynamic analysis, Biochemistry 35 12111912118. 

Wilson, E. K., Mathews, F. S., Packman, L. C., and Scmtton, N. S., 1995, Electron tunneling in substrate-reduced trimethylamine dehydrogenase Kinetics of electron transfer and analysis of the tunneling pathway. Biochemistry 34 2584n2591. 

The foeus of this chapter is the soluble electron transfer complex formed between the nieotinamide-independent trimethylamine dehydrogenase (TMADH) and eleetron transferring flavoprotein (ETF). Recent studies of this physiological electron transfer complex have provided invaluable insight into (i) the mechanisms of inter and intraprotein electron transfer between flavin and Fe/S centers, (ii) the role of dynamics in interprotein electron transfer and (hi) quantum meehanieal mechanisms for the cleavage of substrate C-H bonds and the subsequent transfer of reducing equivalents to flavin redox centers. Brief mention is made of early structural and cofactor analyses for this redox system, but more detailed accounts of this work can be found in earlier reviews on the subjeet (e.g. Steenkamp and Mathews, 1992). 

Steenkamp, D. J., and Beinert, H., 1982a, Mechanistic studies on the dehydrogenases of methylotrophic bacteria. 1. The influence of substrate binding to reduced trimethylamine dehydrogenase on the intramolecular electron transfer between its prosthetic groups, Biochem. J. 207 2339239. 

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