Regioselective acylation of nucleosides and their analogs catalyzed by Pseudomonas cepacia lipase: enzyme substrate recognition
作者:Ning Li、Min-Hua Zong、Ding Ma
DOI:10.1016/j.tet.2008.11.045
日期:2009.1
The substrate recognition of Pseudomonas cepacia lipase in the acylation of nucleosides was investigated by means of rational substrate engineering for the first time. P. cepacia lipase displayed excellent 3′-regioselectivities (96 to >99%) in the lauroylation of 2′-deoxynucleosides 1a–1e, while low to good 3′-regioselectivities (59–89%) in the lauroylation of ribonucleosides 1f–1j. It might be due
首次通过合理的底物工程研究了假单胞菌脂肪酶在核苷酰化中的底物识别。P. cepacia脂肪酶在2'-脱氧核苷1a - 1e的月桂酰化中显示出极好的3'-区域选择性(96至> 99%),而在核糖核苷1f -12的月桂酰化中显示低至良好的3'-区域选择性(59-89%)。1J。这可能是由于1f – 1j的2'-羟基之间不利的氢键相互作用酪氨酸残基中的酪氨酸残基和酚羟基存在于酶的另一个疏水口袋中,可稳定5'-酰化过渡态的构象,从而增加次要区域异构体的数量。此外,脂肪酶成功地合成了氟尿苷的各种酯衍生物,其转化率高(99%),并且在温和条件下具有良好至优异的3'-区域选择性。检查了酶对各种酰基供体的识别。根据脂肪酶活性位点的结构,尤其是大小,形状和理化性质,对酰基的酶促识别是合理的。