Báo cáo khoa học: Increased susceptibility of b-glucosidase from the hyperthermophile Pyrococcus furiosus to thermal inactivation at higher pressures

Increased susceptibility of β-glucosidase from the hyperthermophile Pyrococcus furiosus to thermal inactivation at higher pressures

Authors: Marieke E. Bruins, Filip Meersman, Anja E. M. Janssen, Karel Heremans, and Remko M. Boom

Field: Food and Bioprocess Engineering, Agrotechnology and Food Sciences, Wageningen University and Research Centre; Chemistry, Katholieke Universiteit Leuven

Document Content: This study investigates the stability of β-glucosidase from the hyperthermophile Pyrococcus furiosus as a function of pressure, temperature, and pH. The research utilized FTIR spectroscopy to monitor conformational stability and inactivation studies to assess functional enzyme stability. The enzyme exhibited high piezostability and thermostability, with an unfolding pressure of 800 MPa at 85 °C. A pressure-temperature stability diagram suggests that low pressures stabilize the enzyme against thermal unfolding. Activity measurements revealed a two-step inactivation mechanism influenced by pressure, particularly at lower temperatures, with the second step correlating with conformational changes. Increased pH from 5.5 to 6.5 was found to enhance enzyme stability.

Detailed Table of Contents:

• Keywords: enzyme stability; FTIR spectroscopy; high hydrostatic pressure; intermediate; thermophile
• Correspondence
• Abstract
• Introduction
• Results and Discussion:
• The influence of constant pressure on enzyme inactivation
• Influence of temperature on enzyme inactivation by pressure treatment
• The influence of pH on enzyme inactivation by pressure treatment
• Temperature dependence of the FTIR spectra of β-glucosidase
• Pressure dependence of the FTIR spectra of β-glucosidase
• Conclusions
• Experimental procedures:
• Enzyme purification
• Enzyme inactivation measurements
• Inactivation studies
• Gel electrophoresis
• FTIR spectroscopy
• Acknowledgements
• References