True about reversible non-competitive inhibitors
A variety of poisons, such as iodoacetate, heavy metal ions (lead, mercury) and oxidising agents act as irreversible non-competitive inhibitors. There is no competition between substrate and inhibitor. The inhibitor usually binds to a different domain on the enzyme, other than the substrate binding site. Since these inhibitors have nostructural resemblance to the substrate, an increase in the substrate concentration generally does not relieve this inhibition. The inhibitor combines with the enzymes by forming a covalent bond and then the reaction becomes irreversible. The velocity (Vmax) is reduced. But Km value is not changed, because the remaining enzyme molecules have the same affinity for the substrate. Increasing the substrate concentration will abolish the competitive inhibition, but will not abolish non-competitive inhibition.Ref: DM Vasudevan, Page no: 53
Lower V max
Lower Km
Not affected Km
Not affect V max
Enzymes