Abstract
The pressure effects on thermal inactivation of subtilisin BPN' (S-BPN') and its pressure inactivation have been studied by measuring the rate of hydrolysis of succinyl-l-alanyl-l-alanyl-l-prolyl-l-phenylalanine-p-nitroanilide (SAAPFpNA) catalyzed by S-BPN' in the temperature range of 15-67.5°C and at the pressures up to 700MPa. The apparent rate of hydrolysis decreased with time above a certain temperature and pressure. The decrease is due to the decrease in S-BPN' activity. The enthalpy change of the thermal inactivation was 100-220kJ·mol-1, and the volume change of this process was 18--4cm3·mol-1. While S-BPN' was inactivated in the pressure range of 500-700MPa at 15-45°C, the corresponding volume change was -13--22cm3·mol-1.
