Discovery of selective small-molecule activators of a bacterial glycoside hydrolase

TY - JOUR

T1 - Discovery of selective small-molecule activators of a bacterial glycoside hydrolase

AU - Darby, John F.

AU - Landström, Jens

AU - Roth, Christian

AU - He, Yuan

AU - Davies, Gideon J.

AU - Hubbard, Roderick E.

PY - 2014/12/1

Y1 - 2014/12/1

N2 - Fragment-based approaches are used routinely to discover enzyme inhibitors as cellular tools and potential therapeutic agents. There have been few reports, however, of the discovery of small-molecule enzyme activators. Herein, we describe the discovery and characterization of small-molecule activators of a glycoside hydrolase (a bacterial O-GlcNAc hydrolase). A ligand-observed NMR screen of a library of commercially available fragments identified an enzyme activator which yielded an approximate 90% increase in kcat/KM values (kcat=catalytic rate constant; KM=Michaelis constant). This compound binds to the enzyme in close proximity to the catalytic center. Evolution of the initial hits led to improved compounds that behave as nonessential activators effecting both KM and Vmax values (Vmax=maximum rate of reaction). The compounds appear to stabilize an active "closed" form of the enzyme. Such activators could offer an orthogonal alternative to enzyme inhibitors for perturbation of enzyme activity in vivo, and could also be used for glycoside hydrolase activation in many industrial processes.

AB - Fragment-based approaches are used routinely to discover enzyme inhibitors as cellular tools and potential therapeutic agents. There have been few reports, however, of the discovery of small-molecule enzyme activators. Herein, we describe the discovery and characterization of small-molecule activators of a glycoside hydrolase (a bacterial O-GlcNAc hydrolase). A ligand-observed NMR screen of a library of commercially available fragments identified an enzyme activator which yielded an approximate 90% increase in kcat/KM values (kcat=catalytic rate constant; KM=Michaelis constant). This compound binds to the enzyme in close proximity to the catalytic center. Evolution of the initial hits led to improved compounds that behave as nonessential activators effecting both KM and Vmax values (Vmax=maximum rate of reaction). The compounds appear to stabilize an active "closed" form of the enzyme. Such activators could offer an orthogonal alternative to enzyme inhibitors for perturbation of enzyme activity in vivo, and could also be used for glycoside hydrolase activation in many industrial processes.

KW - Enzyme catalysis

KW - Glycoside hydrolase

KW - Glycosylation

KW - Inhibitors

KW - Protein structures

UR - http://www.scopus.com/inward/record.url?scp=84915820942&partnerID=8YFLogxK

U2 - 10.1002/anie.201407081

DO - 10.1002/anie.201407081

M3 - Article

AN - SCOPUS:84915820942

SN - 1433-7851

VL - 53

SP - 13419

EP - 13423

JO - Angewandte Chemie International Edition

JF - Angewandte Chemie International Edition

IS - 49

ER -