Estimation of rate constants in lysozyme-catalyzed reaction of chitooligosaccharides.

The rate constants of the cleavage of glycoside linkage, hydration (hydrolysis) and transglycosylation in a lysozyme-catalyzed reaction of substrate chitooligosaccharides were evaluated by computer analysis of the experimentally obtained reaction time-courses. In the computer analysis, the rate equation was numerically solved by use of the known binding constants for each subsite. Because of the complexity of the lysozyme-catalyzed reaction, optimal values of rate constants were determined by checking the sensitivity of each rate constant to the computed time-courses. It was not possible to estimate uniquely the rate constants for transglycosylation and hydration, owing to the nature of the enzymatic reaction, but it was possible to estimate accurately their ratio. The estimated values were 0.94 s-1 for the rate constant for the cleavage of glycosidic linkage and 133 for the ratio of rate constants of transglycosylation and hydration.