In silico and in vitro Approaches to Elucidate the Thermal Stability of Human UDP-glucuronosyltransferase (UGT) 1A9
In silico and in vitro Approaches to Elucidate the Thermal Stability of Human UDP-glucuronosyltransferase (UGT) 1A9
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DOI：
10.2133/dmpk.24.235
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发表时间：
2009-01-01
影响因子：
2.1
通讯作者：
Yokoi, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Fujiwara, Ryoichi;Nakajima, Miki;Yokoi, Tsuyoshi
UDP-葡萄糖醛酸转移酶（UGT）是肝脏和肝外组织中主要的药物代谢酶。人UGT 1A 9对热处理具有独特的稳定性。为了理解UGT 1A 9的独特性质，使用TDP-表-万古氨基转移酶的晶体结构作为模板，通过同源建模构建三维结构。序列比对分析显示，与UGT 1A 7、UGT 1A 8和UGT 1A 10相比，UGT 1A 9具有13个独特的氨基酸残基（Arg 42、Lys 91、Ala 92、Tyr 106、Gly 111、Tyr 113、Asp 115、Asn 152、Leu 173、Leu 219、His 221、Arg 222和Glu 241）。为了研究这些残基在UGT 1A 9构象稳定性中的作用，在310 K和360 K下在水溶液中进行了3.0纳秒的结构的分子动力学模拟。均方根偏差分析表明，Arg 42，Leu 173，Leu 219，His 221和Arg 222负责热稳定性。均方根波动分析和动力学互相关图表明，Lys 91，Ala 92，Tyr 106，Gly 111，Tyr 113，Asp 115，Leu 219，His 221，Arg 222和Glu 241负责的热稳定性。使用这些残基突变体的体外研究表明，所有这些氨基酸可能共同参与UGT 1A 9的热稳定性。本文提供的结果为人UGT 1A 9的热稳定性提供了分子基础。
UDP-Glucuronosyltransferases (UGTs) are predominant drug metabolizing enzymes in the liver and extrahepatic tissues. Human UGT1A9 is uniquely stable against heat treatment. To understand the unique properties of UGT1A9, the three-dimensional structure was constructed by homology modeling using a crystal structure of TDP-epi-vancosaminyltransferase as template. Sequence alignment analysis revealed that 13 amino acid residues (Arg42, Lys91, Ala92, Tyr106, Gly111, Tyr113, Asp115, Asn152, Leu173, Leu219, His221, Arg222, and Glu241) are unique to UGT1A9 as compared with UGT1A7, UGT1A8 and UGT1A10. To examine the roles of these residues in the conformational stability of UGT1A9, molecular dynamics simulation of the structures was carried out at 310 K and 360 K in aqueous solution for 3.0 nanoseconds. Root mean square deviation analyses revealed that Arg42, Leu173, Leu219, His221 and Arg222 were responsible for the thermal stability. Root mean square fluctuation analyses and a dynamical cross correlation map revealed that Lys91, Ala92, Tyr106, Gly111, Tyr113, Asp115, Leu219, His221, Arg222 and Glu241 were responsible for the thermal stability. In vitro study using mutants of these residues demonstrated that all these amino acids may be collectively involved in the thermal stability of UGT1A9. The results presented here provide a molecular basis for the thermal stability of human UGT1A9.