An NMR study of the dynamics of inhibitor-induced conformational changes in lysozyme

Abstract

The binding of the inhibitors N-acetyl glucosamine (GlcNAc), the dimer (GlcNAc)* and the trimer (GlcNAc)s to hen egg white lysozyme causes substantial changes in the chemical shift values of a number of resonances in the proton magnetic resonance (pmr) spectrum of the protein, [ 1,2] . These shifts undoubtedly result from conformational changes in the-protein on inhibitor binding. Recently, many of the resonances in the lysozyme pmr spectrum have been assigned to specific protons of residues in the sequence, [2,3,4]. The region of protein involved in the conformational changes can therefore be defined. This paper not only defines the binding regions but also shows that protein pmr may be used to define the rates at which the protein conformational changes occur. Such data are compared to those from previous kinetic studies, thus showing which steps in a rate profile are protein conformational changes.