MWC (concerted) model (all-or-none): assumes that the subunits of a
cooperatively binding protein are functionally identical, that each subunit can
exist in (at least) two conformations, and that all subunits undergo the transition
from one conformation to the other simultaneously (no protein has individual
subunits in different conformation) two conformations are in equilibrium,
Substrate can bind both conformations (different affinity).
• Sequential model: Ligand binding can induce a change of conformation in an individual subunit. A conformational change in one subunit makes a similar change in an adjacent subunit (making binding of secondary subunit more likely)