Kinetics of irreversible inhibition of aminoacylase by MNP

<正> The throl groups of cysteme residues in aminoacylase have been modified by organomercurial, MNP (2-chloromercuri-4-nitrophenol). The kinetics of the inactivation of aminoacylase by MNP followed by the substrate reaction in the presence of the inactivator is dealt, and it is discovered that the inhibition of aminoacylase by MNP is a conformational change type inhibition. Firstly a conformational change of enzyme occurs before reaction of the essential thiol groups of aminoacylse with MNP. In addition, the microscopic rate constants for the conformational change of the enzyme and the reaction of its thiol groups with MNP have been determined.