Stereoselective detoxification of chiral sarin and soman analogues by phosphotriesterase
Stereoselective detoxification of chiral sarin and soman analogues by phosphotriesterase
复制标题
DOI：
10.1016/s0968-0896(01)00113-4
复制
发表时间：
2001-08-01
影响因子：
3.5
通讯作者：
Raushel, FM
中科院分区：
文献类型：
--
作者：
Li, WS;Lum, KT;Raushel, FM
测定了细菌磷酸三酯酶（PTE）对化学战剂沙林和梭曼的一系列手性类似物的催化活性。研究了高对映体过量的O-异丙基对硝基苯基甲基膦酸酯（沙林类似物）的S-P-和R-P-对映体的化学合成方法。沙林类似物的R-P-对映体（k（cat）= 2600 s（-1））相对于相应的S-P-对映体（k（cat）= 290 s（-1））是野生型PTE的优选底物。使用PTE突变体1106 A/F132 A/H254 Y，其中R-P-和S-P-对映异构体的k（cat）值分别为410和4200 s（-1），可逆转观察到的立体选择性。采用化学-酶法合成了高非对映体过量的甲基膦酸邻频哪醇酯对硝基苯酯（梭曼类似物）的4个立体异构体。RPRC-立体异构体的梭曼类似物是PTE的首选底物。梭曼类似物的ka值测量如下：RPRC，48 s（-1）; RPSC，4.8 s（-1）; SPRC，0.3 s（-1）和SPSC，0.04 s（-1）。用PTE的1106 A/F132 A/H254 Y突变体，对手性磷中心的立体选择性被逆转。对于三突变体，梭曼类似物的k（cat）值如下：RPRC，0.3 s（-1）; RPSC，0.3 s（-1）; SPRC，11 s（-1）; SPSC，2.1 s（-1）。先前的研究表明，沙林和梭曼的S-P-对映体比R-P-对映体毒性更大。这项研究表明，突变体的野生型PTE可以很容易地构建增强的催化活性对最有毒的立体异构体沙林和梭曼。(C)2001爱思唯尔科技有限公司版权所有。
The catalytic activity of the bacterial phosphotriesterase (PTE) toward a series of chiral analogues of the chemical warfare agents sarin and soman was measured. Chemical procedures were developed for the chiral syntheses of the S-P- and R-P-enantiomers of O-isopropyl p-nitrophenyl methylphosphonate (sarin analogue) in high enantiomeric excess. The R-P-enantiomer of the sarin analogue (k(cat) = 2600 s(-1)) was the preferred substrate for the wild-type PTE relative to the corresponding S-P-enantiomer (k(cat) = 290 s(-1)). The observed stereoselectivity was reversed using the PTE mutant, 1106A/F132A/H254Y where the k(cat) values for the R-P- and S-P-enantiomers were 410 and 4200 s(-1), respectively. A chemo-enzymatic procedure was developed for the chiral synthesis of the four stereoisomers of O-pinacolyl p-nitrophenyl methylphosphonate (soman analogue) with high diastereomeric excess. The RPRC-stereoisomer of the soman analogue was the preferred substrate for PTE. The ka, values for the soman analogues were measured as follows: RPRC, 48 s(-1); RPSC, 4.8 s(-1); SPRC, 0.3 s(-1), and SPSC, 0.04 s(-1). With the 1106A/F132A/H254Y mutant of PTE the stereoselectivity toward the chiral phosphorus center was reversed. With the triple mutant the k(cat) values for the soman analogues were found to be as follows: RPRC, 0.3 s(-1); RPSC, 0.3 s(-1); SPRC, 11 s(-1), and SPSC, 2.1 s(-1). Prior investigations have demonstrated that the S-P-enantiomers of sarin and soman are significantly more toxic than the R-P-enantiomers. This investigation has demonstrated that mutants of the wild-type PTE can be readily constructed with enhanced catalytic activities toward the most toxic stereoisomers of sarin and soman. (C) 2001 Elsevier Science Ltd. All rights reserved.