Title

NMR Line Shape Analysis of a Multi-state Ligand Binding Mechanism in Chitosanase

Document Type

Article

Language

eng

Publication Date

4-2017

Publisher

Springer

Source Publication

Journal of Biomolecular NMR

Source ISSN

0925-2738

Abstract

Chitosan interaction with chitosanase was examined through analysis of spectral line shapes in the NMR HSQC titration experiments. We established that the substrate, chitosan hexamer, binds to the enzyme through the three-state induced-fit mechanism with fast formation of the encounter complex followed by slow isomerization of the bound-state into the final conformation. Mapping of the chemical shift perturbations in two sequential steps of the mechanism highlighted involvement of the substrate-binding subsites and the hinge region in the binding reaction. Equilibrium parameters of the three-state model agreed with the overall thermodynamic dissociation constant determined by ITC. This study presented the first kinetic evidence of the induced-fit mechanism in the glycoside hydrolases.

Comments

Journal of Biomolecular NMR, Vol. 67, No. 4 (April 2017): 309-319. DOI.