Which of the following is known as suicidal enzyme? (AIIMS November 2013, May 2013)
Ans. b. Cyclooxygenase (Ref: Harper 27/e p204 Harrison 18/e p146Cyclooxygenase is a suicidal enzyme.Suicidal enzyme is one. which undergoes self-destruction in order to terminate its own acitivity. e.g. Cyclooxygenase.Switching off of prostaglandin activity is partly achieved by a remarkable property of cyclooxygenaseQ, that of self-catalyzed destruction, i.e. it is a 'suicidal enzyme'.Suicidal inhibition is conversion of a substrate by the enzyme into a metabolite, which is a potent inhibitor of the enzyme; example: Xanthine oxidase converts allopurinol to alloxanthine (oxypurinol), which is a more potent inhibitor of allopurinol.
Lipoxygenase
Cyclooxygenase
Thromboxane synthatase
5' nucleotidase
Mechanisms of Enzyme Action