Effect of sub‐ and super‐critical CO2 pretreatment on conformation and catalytic properties evaluation of two commercial enzymes of CALB and Lipase PS
Effect of sub‐ and super‐critical CO2 pretreatment on conformation and catalytic properties evaluation of two commercial enzymes of CALB and Lipase PS
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DOI：
10.1002/jctb.4037
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发表时间：
2013-09
影响因子：
3.4
通讯作者：
Yun Liu;Dawei Chen;Shihui Wang
中科院分区：
文献类型：
--
作者：
Yun Liu;Dawei Chen;Shihui Wang
了解亚/超临界CO2预处理对酶构象及其活性的影响是至关重要的，这将提高对非水介质中酶促生物转化应用的理解。本研究评估了亚/超临界CO2处理的效果，包括压力（6和10 MPa），暴露时间（20、30和150分钟）和温度（35和40 °C），在构象上（例如1D、2D和3D结构）和催化性质本文研究了两种商品酶--CALB和PS脂肪酶在溶液中的残活、动力学常数（Km和Vmax）、活化能（Eα）、热稳定性和有机溶剂耐受性。结果与空白对照相比，两种脂肪酶的一维结构无明显变化，二维和三维结构均有不同程度的改变。最高相对活力分别为105%和116%。对于CALB，Vmax/Km值显著增加，而对于脂肪酶PS，Vmax/Km值几乎不变。两种酶均表现出较高的热稳定性，酶活恢复率分别达到76%和80%。此外，这两种处理的酶表现出高的有机溶剂耐受性。结论亚/超临界CO2处理后酶的二维、三维结构发生了变化，可能是酶具有良好催化性能的原因。© 2013化学工业协会
BACKGROUND It is vitally important to understand the effect of sub-/super-critical CO2 pretreatment on enzyme conformation and its activity, which should improve the understanding of enzymatic biotransformation applications in nonaqueous media. This study evaluated the effect of sub-/super-critical CO2 treatment, including pressure (6 and 10 MPa), exposure time (20, 30 and 150 min) and temperature (35 and 40 °C), on the conformation (e.g. 1D, 2D and 3D structures) and catalytic properties (e.g. residual activity, kinetics constants (Km and Vmax), activation energies (Eα), thermo-stability and organic solvent tolerance) of two commercial enzymes, CALB and lipase PS in their solution forms. RESULTS Compared with the blank control, the 1D structure of both treated lipases was unchanged, whereas their 2D and 3D structures were altered to some extent. The highest relative activities were 105% and 116% for CALB and lipase PS, respectively. For CALB, Vmax/Km value significantly increased, while for lipase PS, Vmax/Km value was almost constant. Both treated enzymes showed high thermo-stability with recovery of enzyme activity up to 76% and 80%, respectively. Also, both treated enzymes presented high organic solvent tolerance. CONCLUSIONS It was speculated that 2D, 3D structure alterations were probably responsible for the satisfactory catalytic properties of enzymes treated with sub-/super-critical CO2. © 2013 Society of Chemical Industry