Uncompetitive inhibition

The complementary limit of the branching model permits inhibitor binding only to the enzyme-substrate complex: set $K_i\to \infty$, hence $\alpha =1$, with finite $K_i^{\prime }$. Then both $V_{\max ,\mathrm{app}}$ and $K_{M,\mathrm{app}}$ decrease by ${\alpha }^{\prime }$, while their ratio stays fixed. This limit helps distinguish preferential binding to $ES$ in mixed inhibition from exclusive binding to $ES$ in uncompetitive inhibition.