細菌的十一異戊基二烯焦磷酸合成酶之抑制劑的合成與評測

Abstract

耐甲氧西林金黃色葡萄球菌(methicillin-resistant Staphylococcus aureus)等具多重抗藥性的金黃色葡萄球菌，是種致命且需要新的抗生素治療的醫院感染細菌。十一異戊基二烯焦磷酸合成酶 (undecaprenyl diphosphate synthase, UPPS) 將八當量的異戊烯基焦磷酸 (isopentenyl pyrophosphates, IPP) 與一當量的法尼基焦磷酸(farnesyl pyrophosphate, FPP) 聚合，形成十一異戊基二烯焦磷酸 (undecaprenyl diphosphate, UPP)，是用於合成細菌細胞壁的肽聚醣的必要前驅物，因此十一異戊基二烯焦磷酸合成酶可作為新抗生素的標靶。基於十一異戊基二烯焦磷酸合成酶之結構和先前的研究，我們設計了一系列吡咯烷酮的衍生物，並使用法尼基焦磷酸的螢光衍生物MANT-O-GPP的活性測試法來測試它們對大腸桿菌及金黃色葡萄球菌之十一異戊基二烯焦磷酸合成酶的抑制作用，其中具有鹵素或苯基的化合物對抑制十一異戊基二烯焦磷酸合成酶更有效，而最小抑菌濃度的測試結果表明它們具有抑制枯草桿菌 (Bacillus subtilis) 的活性，根據酵素動力學和結構模擬，這些化合物對十一異戊基二烯焦磷酸合成酶而言是混合型的抑制劑。

The multiple antibiotic-resistant Staphylococcus aureus, such as methicillin-resistant Staphylococcus aureus (MRSA), is a fatal nosocomial infection that needs new antibiotics. Undecaprenyl diphosphate synthase (UPPS) condenses a farnesyl pyrophosphate (FPP) with eight isopentenyl pyrophosphates (IPP) to form undecaprenyl diphosphate (UPP) for the biosynthesis of peptidoglycan essential for bacterial cell wall, so it is a potential drug target for antibiotic. Based on UPPS structure and previous research, we designed a series of 4-carboxy-1-(4-styrylcarbonylphenyl)-2-pyrrolidinone derivatives and used a fluorescent analog of FPP, MANT-O-GPP, to test their inhibition on E. coli and MRSA UPPS. The compounds with halogen or benzene group were more potent to inhibit UPPS. Then, the EC50 test showed that they have anti-bacterial activities to Bacillus subtilis. According to the enzyme kinetics and modeling, these compounds were mixed inhibitors of UPPS.