An ultracentrifugal approach to quantitative characterization of the molecular assembly of a physiological electron-transfer complex: the interaction of electron-transferring flavoprotein with trimethylamine dehydrogenase.
The interaction between two physiological redox partners, trimethylamine dehydrogenase and electron-transferring flavoprotein, has been characterized quantitatively by analytical ultracentrifugation at 4 degrees C. Analysis of sedimentation-equilibrium distributions obtained at 15 000 rpm for mixtures in 10 mM potassium phosphate, pH 7.5, by means of the psi function [Wills, P. R., Jacobsen, M. P. & Winzor, D. J. (1996) Biopolymers 38, 119-130] has yielded an intrinsic dissociation constant of 3-7 microM for the interaction of electron-transferring flavoprotein with two equivalent and independent sites on the homodimeric enzyme. This investigation indicates the potential of sedimentation equilibrium for the quantitative characterization of interactions between dissimilar macromolecules.
Wilson
E K
EK
Department of Biochemistry, University of Leicester, UK.
Scrutton
N S
NS
Cölfen
H
H
Harding
S E
SE
Jacobsen
M P
MP
Winzor
D J
DJ
D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry; D004579:Electron Transport; D044927:Electron-Transferring Flavoproteins; D005420:Flavoproteins / Q000737:chemistry*; D046911:Macromolecular Substances; D010089:Oxidoreductases, N-Demethylating / Q000737:chemistry*; D011485:Protein Binding; D014461:Ultracentrifugation
D001426:Bacterial Proteins; D044927:Electron-Transferring Flavoproteins; D005420:Flavoproteins; D046911:Macromolecular Substances; D010089:Oxidoreductases, N-Demethylating; C023186:trimethylamine dehydrogenase