Amicosante G, Oratore A, Marinucci M C, Tizzani M I, Scazzocchio F, Crifo C, Strom R
Biochem Int. 1987 Jan;14(1):15-26.
p-Hydroxymercuribenzoate is a non-competitive inhibitor of beta-lactamase I from Bacillus cereus and also, after preliminary preincubation, an inactivator of the enzyme. Submitted to the simultaneous action of PCMB plus dicloxacillin, the enzyme completely loses its activity. Extensive dialysis can restore the enzymatic activity only if preincubation had been carried out with either PCMB or dicloxacillin but not if both inhibitors had been simultaneously present. Mercaptoethanol protects the enzyme from the action of PCMB, but not from the severe inactivation caused by dicloxacillin-PCMB mixtures. All these data suggest the formation of a complex between PCMB and the acyl-enzyme intermediate generated upon hydrolysis of the beta-lactam bond of dicloxacillin.
对羟基汞苯甲酸是蜡状芽孢杆菌β-内酰胺酶I的非竞争性抑制剂，并且在初步预孵育后，也是该酶的失活剂。在PCMB和双氯西林同时作用下，该酶完全丧失活性。只有在使用PCMB或双氯西林进行预孵育时，广泛透析才能恢复酶活性，而如果两种抑制剂同时存在则不能恢复。巯基乙醇可保护该酶免受PCMB的作用，但不能保护其免受双氯西林-PCMB混合物引起的严重失活。所有这些数据表明，PCMB与双氯西林β-内酰胺键水解产生的酰基酶中间体之间形成了复合物。
