Monod-Wyman-Changeux Equation
by Mike Martin

This page generates a plot of the Monod-Wyman-Changeux Equation:

The equation/model helps to explain sigmoidal enzyme kinetics taking into consideration the interaction of the enzyme's subunits.   In the model it is assumed that (1) the enzyme consists of n identical subunits, (2) each subunit can assume an active (R) or an inactive (T) conformation, (3) all subunits change their conformations at the same time, and (4) the equilibrium between the two states, R and T, is given by an allosteric constant, L.   v0 is the dependent variable and represents the velocity of the reaction as a function of the substrate concentration, s, the independent variable.   vmax represents the value of the maximum velocity of the reaction, KR and KT represent the binding constants for the two conformations, L is the allosteric constant, and n is the Hill coefficient (equal to the number of subunits in this case).

Enter in the values of the non-negative parameters vmax, KR, KT, L, and n and select the plotting bounds, then press the "Evaluate" button.

vmax =  

KR =  

KT =  

L =  

n =  

  ≤   s   ≤  


References:

Changeux, J.P. (1964). Allosteric interactions interpreted in terms of quaternary structure. Brookhaven Symposia in Biology, 17: 232-249.

Monod, J., J. Wyman, and J.P. Changeux (1965). On the nature of allosteric transitions: a plausible model. J. Mol. Biol., 12: 88-118.

S.J. Edelstein (1971). Extensions of the allosteric model for hemoglobin. Nature, 230:224-227.

Changeux JP, Edelstein SJ (1998). Allosteric receptors after 30 years. Neuron, 21: 959-980.

T.A. Duke, N. Le Novere, D. Bray (2001). Conformational spread in a ring of proteins: a stochastic approach to allostery. J. Mol Biol, 308:541-553.

Changeux J.P., S.J. Edelstein (2005). Allosteric mechanisms of signal transduction. Science, 2005 Jun 3;308(5727):1424-8.

Klipp, E, R Herwig, A Kowald, C Wierling, H Lehrach Systems Biology in Practice. Wiley, Berlin, Germany, 2005.