Thermal inactivation kinetics of penicillin g acylase obtained from a mutant derivative of escherichia coli atcc 11105

Thermal inactivation kinetics of native and glutaraldehyde cross-linked forms of penicillin G acylase obtained from a mutant derivative of Escherichia coli ATCC 11105 were studied. Apparent activation energies for thermal inactivation of both native and cross-linked forms of enzyme were calculated to be [57.71 +/- 8.46] and [67.11 +/- 13.83] kcal mol-1 respectively. This slight increase in activation energy suggested that glutaraldehyde cross-linking did not markedly protect against thermal activation. Cross-linked enzyme did, however, have a significantly improved half-life at temperatures between 40 degrees C and 50 degrees C.