A new study of the degradation of hyaluronic acid by hyaluronidase using quartz crystal impedance technique

A new quartz crystal impedance sensing technique for the assay of hyaluroni dase (HAse) activity is presented. It is based on the changes in viscosity and density during the enzymatic hydrolysis of hyaluronic acid (HA) by HAse . The variations of equivalent circuit parameters of piezoelectric quartz c rystal (PQC) during the enzymatic degradation are discussed. The motional r esistance shift curves indicate that the viscosity of the test solutions de creases during the hydrolysis process. The initial hydrolysis rates of HA a re obtained from changes in viscosity and density as a function of incubati on time. Kinetic parameters (the Michaelis constant K-m and the maximum hyd rolysis rate V-max) of the degradation reaction are estimated by using a li near Lineweaver-Burk plot in this work. The K-m was 0.44 +/- 0.03 mg.ml(-1) and the V-max was - (5.29 +/- 0.36) x 10(-3) kg.m(-2).s(-1).min(-1). (C) 2 001 Elsevier Science B.V. All rights reserved.