Figure 3.

States and weights for a MWC enzyme. The energies ε_A and ε_I provide the free energy scale for the substrate-free conformations, dictating their relative probabilities. Decreasing the energy ε_A of the active state would increase the probability of all the active enzyme conformations relative to the inactive conformations. $K_{\mathrm{M}}^{\mathrm{A}}$ denotes the substrate concentration at which half of the active enzymes are bound and half of the active enzymes are unbound, as indicated by the crossing of the (p_EA, blue) and (p_EAS, gold) curves at $[\mathrm{S}]=K_{\mathrm{M}}^{\mathrm{A}}$ in Figure 4. $K_{\mathrm{M}}^{\mathrm{I}}$ serves an analogous role for the inactive states.