作者:Pin Wang、Yi Tang、David A. Tirrell
DOI:10.1021/ja0298287
日期:2003.6.1
Two fluorinated derivatives of isoleucine: d,l-2-amino-3-trifluoromethyl pentanoic acid (3TFI, 2) and d,l-2-amino-5,5,5-trifluoro-3-methyl pentanoic acid (5TFI, 3) were prepared. 5TFI was incorporated into a model target protein, murine dihydrofolate reductase (mDHFR), in an isoleucine auxotrophic Escherichia coli host strain suspended in 5TFI-supplemented minimal medium depleted of isoleucine. Incorporation
异亮氨酸的两种氟化衍生物:d,l-2-amino-3-trifluoromethyl pentanoic acid (3TFI, 2) 和 d,l-2-amino-5,5,5-trifluoro-3-methylpentanoic acid (5TFI, 3 ) 准备好了。5TFI 被纳入模型靶蛋白,鼠二氢叶酸还原酶 (mDHFR),在异亮氨酸营养缺陷型大肠杆菌宿主菌株中,悬浮在缺乏异亮氨酸的 5TFI 补充的基本培养基中。通过蛋白质产物的胰蛋白酶肽分析和基质辅助激光解吸电离质谱 (MALDI-MS) 证实了 5TFI 的掺入。氨基酸分析表明,超过 93% 的编码异亮氨酸残基被 5TFI 取代。大肠杆菌异亮氨酰-tRNA 合成酶 (IleRS) 对 5TFI 的活化率的测量产生了比异亮氨酸低 134 倍的特异性常数 (k(cat)/K(m))。5TFI 在编码的异亮氨酸位置成功引入细胞因子鼠白细胞介素