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

• After treated at 450 MPa and 40 °C for 10 min, the maximum activity of Lip2 was approximately twice as control.
• The dwell time had a great influence on the enzyme activity.
• The changes of secondary structure of Lip2 under high pressure were investigated.
• The hydrophobic environment of Trp residues in Lip2 was hardly perturbed by pressure.
• The combined effects of pressure-temperature on Lip2 were expressed in an isokineticity diagram.

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 450 MPa and 40 °C for 10 min, 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.

Figure optionsDownload as PowerPoint slide