Allopurinol inhibits which enzyme?: (A) Xanthine oxidase, (B) Kinase, (C) Lysyl oxidase, (D) Cyclooxygenase
Answer is A. Allopurinol inhibits Xanthine oxidase Mechanism-based inhibition/Suicidal inhibitors resemble the actual substrate of the enzyme. Enzymes binds to suicidal inhibitor & catalytic process is staed. In the process of catalysis, enzyme undergoes irreversible covalent modification by the inhibitor & active enzyme can't be regenerated. (Enzyme catalyses its own destruction) Suicidal Inhibitor Enzyme Allopurinol Xanthine oxidase Aspirin Cyclooxygenase 5-FU Thymidylate synthase Penicillin Transpeptidase Difluoromethylornithine Ornithine decarboxylase