Department of Drug Metabolism and Pharmaceutical Analysis, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
Biochem Pharmacol. 2011 Dec 1;82(11):1757-63. doi: 10.1016/j.bcp.2011.08.004. Epub 2011 Aug 11.
Flurbiprofen (FPF), available commercially as a racemic mixture, is a propionic acid derivative of non-steroidal anti-inflammatory drugs (NSAIDs) with known stereoselective glucuronidation. The major enzyme catalyzing this conjugation reaction is UDP-glucuronosyltransferase (UGT) 2B7, with minor contributions by UGT1A9. This study examines the role of the genetic variants of UGT2B7 and 1A9 enzymes involved in the formation of acyl glucuronides (FPFGs). Variants caused by three single nucleotide polymorphisms (SNPs) (A71S, 211G>T; H268Y, 802C>T; and D398N, 1192G>A) in UGT2B7 and three SNPs (C3Y, 8G>A; M33T, 98T>C; D256N, 766G>A) in UGT1A9 showed activity changes toward different substrates. However the functional impacts of these SNPs on chiral substrates were not examined. Upon stable expression in Bac-to-Bac system, UGT2B771S (A(71)S), UGT2B72 (H(268)Y) and UGT2B75 (D(398)N) were all associated with a decrease in the formation of FPFGs. Compared with UGT2B71 (wild-type), UGT2B771S exhibited a >2-fold lower intrinsic clearance mainly by altered capacities (V(max)). Furthermore, a >14-fold decreased intrinsic clearance of the 1 protein was produced by UGT2B72 and UGT2B75. However, no significantly stereoselective difference for the formation of (R)- and (S)-FPFG was found among these UGT2B7 allozymes. UGT1A92 (C(3)Y) exhibited a higher V(max) (3.2-fold), K(m) (2.1-fold) and intrinsic clearance (1.6-fold) toward (S)-FPF than UGT1A91 (wild-type). UGT1A9*3 (M(33)T) almost lost the catalytic activity to FPF. A significantly stereoselective difference on the glucuronidation of rac-FPF was seen between the two variants compared with the wild type of UGT1A9.
氟比洛芬（FPF），以外消旋混合物的形式市售，是一种已知具有立体选择性葡萄糖醛酸化的非甾体抗炎药物（NSAIDs）的丙酸衍生物。催化该结合反应的主要酶是 UDP-葡糖醛酸基转移酶（UGT）2B7，UGT1A9 也有少量贡献。本研究探讨了参与酰基葡萄糖醛酸化物（FPFGs）形成的 UGT2B7 和 1A9 酶的遗传变异体的作用。UGT2B7 中的三个单核苷酸多态性（SNPs）（A71S、211G>T；H268Y、802C>T；和 D398N、1192G>A）和 UGT1A9 中的三个 SNPs（C3Y、8G>A；M33T、98T>C；D256N、766G>A）引起的变体对不同的底物显示出活性变化。然而，这些 SNP 对手性底物的功能影响尚未被检查。在 Bac-to-Bac 系统中稳定表达后，UGT2B771S（A71S）、UGT2B72（H268Y）和 UGT2B75（D398N）均与 FPFGs 形成减少有关。与 UGT2B71（野生型）相比，UGT2B771S 表现出 >2 倍的内在清除率，主要是由于能力（Vmax）改变。此外，UGT2B72 和 UGT2B75 产生的 UGT2B71 蛋白的内在清除率降低了 >14 倍。然而，在这些 UGT2B7 同种型中，（R）-和（S）-FPFG 的形成并没有发现明显的立体选择性差异。UGT1A92（C3Y）对（S）-FPF 的 Vmax（3.2 倍）、K m（2.1 倍）和内在清除率（1.6 倍）均高于 UGT1A91（野生型）。UGT1A9*3（M33T）几乎失去了对 FPF 的催化活性。与野生型 UGT1A9 相比，两种变体在 rac-FPF 的葡萄糖醛酸化方面显示出明显的立体选择性差异。
