Structural basis for thermostability revealed through the identification and characterization of a highly thermostable phosphotriesterase-like lactonase from Geobacillus stearothermophilus.
Structural basis for thermostability revealed through the identification and characterization of a highly thermostable phosphotriesterase-like lactonase from Geobacillus stearothermophilus.
复制标题
DOI：
10.1016/j.abb.2009.06.005
复制
发表时间：
2009-08-15
影响因子：
3.9
通讯作者：
Mesecar AD
中科院分区：
文献类型：
--
作者：
Hawwa R;Aikens J;Turner RJ;Santarsiero BD;Mesecar AD
从嗜热脂肪土芽孢杆菌（Geobacillusstearothermophilus，GsP）中鉴定出一种与磷酸三酯酶同源的新酶。这种酶属于酰胺水解酶家族，具有水解内酯和有机磷酸酯（OP）化合物的能力，使其成为磷酸三酯酶样内酯酶（PLL）。GsP具有比最近表征的PLL更高的OP降解活性，并且它是非常热稳定的。GsP在高达100°C下具有活性，对乙基对氧磷的活化能为8.0 kcal/mol，并且它可以承受60°C的孵育温度两天。为了了解PLL的热稳定性，测定了GsP的X射线结构，并与现有PLL的X射线结构进行了比较。基于比较分析，开发了新的热优势评分和图表，并揭示了许多不同的因素对PLL的热稳定性有影响。
A new enzyme homologous to phosphotriesterase was identified from the bacterium Geobacillus stearothermophilus (GsP). This enzyme belongs to the amidohydrolase family and possesses the ability to hydrolyze both lactone and organophosphate (OP) compounds, making it a phosphotriesterase-like lactonase (PLL). GsP possesses higher OP-degrading activity than recently characterized PLLs, and it is extremely thermostable. GsP is active up to 100°C with an energy of activation of 8.0 kcal/mol towards ethyl paraoxon, and it can withstand an incubation temperature of 60°C for two days. In an attempt to understand the thermostability of PLLs, the X-ray structure of GsP was determined and compared to those of existing PLLs. Based upon a comparative analysis, a new thermal advantage score and plot was developed and reveals that a number of different factors contribute to the thermostability of PLLs.