Bruins Marieke E, Meersman Filip, Janssen Anja E M, Heremans Karel, Boom Remko M
Food and Bioprocess Engineering Group, Department of Agrotechnology and Food Sciences, Wageningen University and Research Centre, The Netherlands.
FEBS J. 2009 Jan;276(1):109-17. doi: 10.1111/j.1742-4658.2008.06759.x.
The stability of beta-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 degrees 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.
研究了嗜热古菌激烈火球菌（Pyrococcus furiosus）中β-葡萄糖苷酶的稳定性与压力、温度和pH的关系。使用傅里叶变换红外光谱（FTIR）监测构象稳定性，并通过失活研究监测功能性酶的稳定性。该酶被证明具有高度的耐压稳定性和热稳定性，在85℃时的解折叠压力为800MPa。初步的压力-温度稳定性图表明，该酶在低压下对热解折叠具有稳定作用。活性测量显示，由于压力导致的失活机制分两步进行，在较低温度下最为明显。这种失活的第一部分发生在300MPa以下的压力下，且未表现为构象转变。活性的第二次转变与构象转变同时发生。发现pH从5.5增加到6.5具有稳定作用。
