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

The stability ofb-glucosidase from the hyperthermophile Pyrococcus furio-suswas studied as a function of pressure, temperature and pH. The confor-mational stability was monitored using FTIR spectroscopy, and the functional enzyme stability was monitored by inactivation studies. | Increased susceptibility of b-glucosidase from the hyperthermophile Pyrococcus furiosus to thermal inactivation at higher pressures Marieke E. Bruins1 Filip Meersman2 Anja E. M. Janssen1 Karel Heremans2 and Remko M. Boom1 1 Food and Bioprocess Engineering Group Department of Agrotechnology and Food Sciences Wageningen University and Research Centre The Netherlands 2 Department of Chemistry Katholieke Universiteit Leuven Belgium Keywords enzyme stability FTIR spectroscopy high hydrostatic pressure intermediate thermophile Correspondence A. E. M. Janssen Food and Bioprocess Engineering Group Department of Agrotechnology and Food Sciences Wageningen University and Research Centre PO Box 8129 6700 EV Wageningen The Netherlands Fax 31 317 482237 Tel 31 317 482231 E-mail Received 26 August 2008 revised 2 October 2008 accepted 24 October 2008 doi The stability of b-glucosidase from the hyperthermophile Pyrococcus furio-sus was studied as a function of pressure temperature and pH. The conformational stability was monitored using FTIR spectroscopy and the functional enzyme stability was monitored by inactivation studies. The enzyme proved to be highly piezostable and thermostable with an unfolding pressure of 800 MPa at 85 C. The tentative pressure-temperature stability diagram indicates that this enzyme is stabilized against thermal unfolding at low pressures. The activity measurements showed a two-step inactivation mechanism due to pressure that was most pronounced at lower temperatures. The first part of this inactivation took place at pressures below 300 MPa and was not visible as a conformational transition. The second transition in activity was concomitant with the conformational transition. An increase in pH from to was found to have a stabilizing effect. b-Glucosidases catalyse the hydrolysis of b-O-gluco-sidic bonds with broad substrate specificity 1 . The b-glucosidase from the hyperthermophile .

• Báo cáo khoa học
• medical reports
• thesis report
• traditional medicine
• Crystal structure
• medical analysis
• biochemical studies
• statements and documents scientific reports
• medical knowledge
• medical research
• clinical trials
• medical management
• health care
• medical transfer
• the developing countries