(biochemistry) A model used to describe the allosteric forms of cooperativity
The Monod-Wyman-Changeux model is proposed by Jean-Pierre Changeux (a French biochemist) and described by Jacques Monod (a French biologist), and Jeffries Wyman. The model describes the allosteric transitions of proteins comprised of same subunits. In this model, the oligomeric protein may exist in two conformational states in the absence of the ligand. These states are in equilibrium and the one that is predominant has a lower affinity for the ligand. In this model, the allosteric protein is an oligomer of protomers that are functionally identical. A protomer refers to each allosteric unit. The protomer may occur in two conformational states, i.e. tense state (T) and relaxed state (R). Nevertheless, all protomers of a molecule must be in the same state. They must all be in a tense state or in a relaxed state. Furthermore, the protomers are in equilibrium whether or not a ligand is attached to the oligomer. The ligand may bind to a protomer in either state. However, the protomer that is in relaxed state has a higher affinity for the ligand compared with that in tense state.
Abbreviation / Acronym: MWC model
- concerted model
- symmetry model