Behavior of Yarrowia lipolytica Lipase Lip2 under high hydrostatic pressure: Conformational changes and isokineticity diagram

Abstract

Despite the large and increasing interest in Yarrowia lipolytica Lipase Lip2 (Lip2) for biotransformation in food processing, the effect of conformational changes and isokineticity diagram on Lip2’s behaviour still remains unclear. In this paper, the catalytic ability of Lip2 under high hydrostatic pressure was investigated. After treated at 450MPa and 40°C for 10min, the maximum enzyme activity was obtained, which was 209% of that at atmospheric pressure. Changes of the secondary and tertiary structure of Lip2 were characterized using circular dichroism and fluorescence spectra. The isokineticity diagram for the combined effects of pressure-temperature on denaturation of enzyme was established. The elliptical shape of the diagram was close to that deduced from thermodynamics, indicating the stabilization of Lip2 against thermal denaturation. These results showed that pressure has a remarkable effect on the stabilization of Lip2.