Scheme 3.

Whereby E is the free/active enzyme form, ES, the enzyme-substrate complex, D is denaturant such as urea or GdnHCl; F, an inactive urea denatured enzyme form; G, an intermediate enzyme form; S, substrate. I′, I′′, I′′′, and I′′′′ are increasing concentrations of ligand (e.g., galactose), E ⁿ S is enzyme-substrate complex whereby n represents various conformational states of enzyme bound to substrate, E ⁿ I is enzyme-inhibitor complex whereby n represents various conformational states of enzyme bound to inhibitor and P, product, E ⁿ S I is enzyme-substrate-inhibitor complex whereby n represents various conformational states of enzyme bound to substrate and inhibitor complex.