Nucleophilic displacement reactions lysozymes

Lysozyme Uses Two Successive Nucleophilic Displacement Reactions... 

Lysozyme makes use of covalent catalysis and general acid catalysis as it promotes two successive nucleophilic displacement reactions. 

This illustrates the fact that the proper positioning of a group (electrophilic or nucleophilic) may accelerate the rate of a reaction. There is thus an analogy to be made with the active site of an enzyme such as lysozyme. Of course the nature of the leaving group is also important in describing the properties. Furthermore, solvation effects can be of paramount importance for the course of the transformation especially in the transition state. Reactions of this type are called assisted hydrolysis and occur by an intramolecular displacement mechanism steric factors may retard the reactions. 

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