抗癌天然产物吡咯替尼选择性靶向α-微管蛋白的Lys352。

The anticancer natural product pironetin selectively targets Lys352 of alpha-tubulin.

作者信息

Usui Takeo, Watanabe Hiroyuki, Nakayama Hiroshi, Tada Yukio, Kanoh Naoki, Kondoh Masuo, Asao Tetsuji, Takio Koji, Watanabe Hidenori, Nishikawa Kiyohiro, Kitahara Takeshi, Osada Hiroyuki

机构信息

Antibiotics Laboratory, RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.

出版信息

Chem Biol. 2004 Jun;11(6):799-806. doi: 10.1016/j.chembiol.2004.03.028.

DOI:10.1016/j.chembiol.2004.03.028

PMID:15217613

Abstract

Pironetin is a potent inhibitor of tubulin assembly and arrests cell cycle progression in M phase. Analyses of its structure-activity relationships suggested that pironetin covalently binds tubulin. To determine the binding site of pironetin, we synthesized biotinylated pironetin, which inhibited tubulin assembly both in vitro and in situ. The biotinylated pironetin selectively and covalently bound with tubulin. Partial digestion of biotinylated pironetin-treated tubulin by several proteases revealed that the binding site is the C-terminal portion of alpha-tubulin. By systematic alanine scanning, the pironetin binding site was determined to be Lys352 of alpha-tubulin. Lys352 is located at the entrance of a small pocket of alpha-tubulin, and this pocket faces the beta-tubulin of the next dimer. This is the first compound that covalently binds to the alpha subunit of tubulin and Lys352 of alpha-tubulin and inhibits the interaction of tubulin heterodimers.

摘要

吡咯菌素是一种有效的微管蛋白组装抑制剂，可使细胞周期进程停滞在M期。对其构效关系的分析表明，吡咯菌素与微管蛋白共价结合。为确定吡咯菌素的结合位点，我们合成了生物素化的吡咯菌素，它在体外和原位均能抑制微管蛋白组装。生物素化的吡咯菌素与微管蛋白选择性地共价结合。用几种蛋白酶对经生物素化吡咯菌素处理的微管蛋白进行部分消化后发现，结合位点是α-微管蛋白的C末端部分。通过系统的丙氨酸扫描，确定吡咯菌素的结合位点是α-微管蛋白的Lys352。Lys352位于α-微管蛋白一个小口袋的入口处，这个口袋面向下一个二聚体的β-微管蛋白。这是第一种与微管蛋白的α亚基和α-微管蛋白的Lys352共价结合并抑制微管蛋白异二聚体相互作用的化合物。