HIGH-PRESSURE-INDUCED COMPLEXES OF ALPHA-CHYMOTRYPSIN WITH BLOCK-COPOLYMERS BASED ON ETHYLENE AND PROPYLENE OXIDES

A new method for formation of non-covalent adducts based on amphophili c diblock copolymer of ethylene and propylene oxides with molecular ma ss of 2 kD and alpha-chymotrypsin (ChT) under high pressure has been d eveloped. The composition of the complexes corresponds to seven polyme r molecules per molecule of ChT in the pressure range from 1.1 to 400 MPa. The complexes fully retain the catalytic activity of ChT. Kinetic constants (K-m and k(cat)) for the enzymatic hydrolysis of N-benzoyI- L-tyrosine ethyl ester catalyzed by complexes are identical to the cor responding values for native ChT. Investigation of the kinetics of the rmal inactivation of the complexes showed that the rate constant for t he slow inactivation step is markedly lower than for ChT.