Tris inhibits a GH1 β-glucosidase by a linear mixed inhibition mechanism.

ABSTRACT: Here we demonstrate that Tris (2-amino-2-(hydroxymethyl)-1,3-propanediol), largely used as a buffering agent, is a linear mixed inhibitor (Ki =  12 ±  2 mM and α =  3 ±  1) of the GH1 β-glucosidase from the insect Spodoptera frugiperda (Sfβgly). Such an inhibition mechanism implies the formation of a non-productive ESI complex involving Sfβgly, substrate, and Tris. In addition, Tris binding reduces by 3 fold the enzyme affinity for the substrate. Hence, at concentrations higher than the Ki, Tris can completely abolish Sfβgly activity, whereas even at lower concentrations the presence of Tris causes underestimation of β-glucosidase kinetic parameters (Km and kcat). In agreement with the inhibition mechanism, computational docking showed that Tris could bind to a pocket placed at the lateral

SUBMITTER: Chagas RS 

PROVIDER: S-EPMC11936226 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature