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Increased susceptibility of β‐glucosidase from the hyperthermophile Pyrococcus furiosus to thermal inactivation at higher pressures
Author(s) -
Bruins Marieke E.,
Meersman Filip,
Janssen Anja E. M.,
Heremans Karel,
Boom Remko M.
Publication year - 2009
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2008.06759.x
Subject(s) - pyrococcus furiosus , hyperthermophile , chemistry , food science , biochemistry , archaea , gene
The stability of β‐glucosidase from the hyperthermophile Pyrococcus furiosus 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 5.5 to 6.5 was found to have a stabilizing effect.