Uncompetitive inhibitors

Uncompetitive inhibitors are one of three reversible enzyme inhibitors.

They are similar to a non-competitive inhibitor, as they utilise a binding site away from the enzyme active site, but uncompetitive inhibitors only bind to an enzyme-substrate complex^[1], rather than free enzymes.

Effect on V_max and K_m

Uncompetitive inhibitors decrease both Vmax and K_m^[2]. The V_max decreases as the inhibitor prevents the enzyme-substrate complex from completing the reaction and releasing products. K_m decreases due to the enzyme-substrate complex being unable to dissociate, which increases the enzyme's affinity for the substrate.

References

1. ↑ V.Leskovac,(2003) Comprehensive enzyme kinetics. New York:Kluwer academic/Plenum Publishers
2. ↑ T.Palmer,P.L.Bonner,(2007) Enzymes:Biochemistry,biotechnology,clinical chemistry, 2nd edition. Elsevier science and technology