Kinetics of glycosyl hydrolase family 2 beta-glucuronidases

Conference Dates

September 15-19, 2019


Glucuronidases serve important roles in physiology, research, and commercial applications. Bacteria of the microbiome produce β-glucuronidase (β-GUS) to scavenge glucuronic acid from compounds excreted via phase II metabolism. In research, β-GUS is commonly used as a reporter for gene expression. Commercially, β-GUS is used in clinical and forensic drug testing to cleave glucuronic acid from drug molecules making them easier to quantify by LC-MS. Minimally, the enzyme must form a homodimer for activity, and the naturally occurring active form is believed to be a tetramer. Past studies have investigated hydrolysis activity of the enzyme and modeled it as simple Michaelis-Menten kinetics. In our search for new enzymes and enzyme variants, we discovered a point mutation that radically alters the kinetics of the enzyme and points to a strong allosteric interaction between enzyme subunits. We further observe substrate inhibition and consider inhibition by competing substances found in clinical samples. Here we survey several different enzymes and variants across multiple substrates and present models for evaluating enzyme performance.

Please click Additional Files below to see the full abstract.

This document is currently not available here.