THERMAL-STABILITY OF L-LYSINE-ALPHA-OXIDASE FROM TRICHODERMA SP

The irreversible thermal inactivation of L-lysine-alpha-oxidase is a process whose initial step is reversible denaturation, accompanied by irreversible aggregation of the denatured molecules. This process is complicated by dissociation of the L-lysine-alpha-oxidase molecules into subunits, followed by irreversible aggregation of individual subunits. The combination of these factors gives a complex law of the inactivation kinetics, which in general is the superposition of two second-order kinetic laws. On the basis of an analysis of the kinetic laws of inactivation of L-lysine-alpha-oxidase it is suggested that the dissociation of the enzyme molecules into individual subunits is a stabilizing factor, which substantially decelerates the process of thermal inactivation.