Use of a quartz crystal impedance technique to monitor the degradation of chondroitin sulfate by hyaluronidase

A new quartz crystal impedance hyaluronidase sensing technique, which is based on the changes in viscosity and density during the enzymatic hydrolysis of chondroitin sulfate (CS) by hyaluronidase (HAse), is established in this paper. The variations of equivalent circuit parameters of the piezoelectric quartz crystal (PQC) during the enzymatic degradation are discussed. The initial hydrolysis rate of CS by HAse is obtained from the changes in viscosity and density with incubation time. Kinetic parameters (the Michaelis constant Km and the maximum hydrolysis rate Vmax) of the degradation process are estimated by using a linear method of Lineweaver-Burk plot. Km is 2.73 ± 0.20 mg·ml−1 and Vmax is -(5.43 ± 0.38) × 10−4 kg·m−2·s−1/2·min−1.