Enzyme Uncompetitive Inhibition Calculator

Uncompetitive inhibition occurs when an inhibitor binds only to the enzyme-substrate complex (ES), not to the free enzyme. This type of inhibition decreases both Vmax and Km proportionally, making the enzyme less effective overall.

In competitive inhibition, the inhibitor competes with substrate for the active site. In uncompetitive inhibition, the inhibitor only binds to the enzyme-substrate complex, so it cannot be overcome by increasing substrate concentration.

Ki represents the dissociation constant for the inhibitor binding to the enzyme-substrate complex. A lower Ki value indicates stronger inhibitor binding and more potent inhibition.

In uncompetitive inhibition, both apparent Km and Vmax decrease by the same factor (1 + [I]/Ki). The apparent Km decreases because the inhibitor removes ES complex from equilibrium, while Vmax decreases due to reduced enzyme availability.

The inhibition factor (1 + [I]/Ki) shows how much the enzyme activity is reduced. A factor of 2 means the enzyme operates at 50% of its uninhibited rate.

No, uncompetitive inhibition cannot be overcome by increasing substrate concentration. In fact, higher substrate concentrations may increase inhibition since more ES complex is available for inhibitor binding.

Ki values vary widely depending on the enzyme-inhibitor pair, ranging from nanomolar (very potent) to millimolar (weak inhibition). Most drug inhibitors have Ki values in the micromolar range.

Uncompetitive inhibition is valuable in drug design because it cannot be overcome by substrate competition and becomes more effective at higher substrate concentrations, which often occur in disease states.