2015-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/659827摘要：抗多種抗生素之金黃色葡萄球菌的出現和流行已經在臨床治療上造成了嚴重的問題。因此，開發新型抗葡萄球菌的藥物已成為公眾健康上一個迫切需求。先前，我們已經成功從抗發炎藥物 celecoxib的衍生物中，找到數個在 sub-μg/mL濃度即對金黃色葡萄球菌和耐甲氧西林金黃色葡萄球菌（MRSA）在培養基中的生長具強有力抑制活性之抗葡萄球菌藥物。此外，單次的腹腔給予最有潛力的藥劑(30毫克/公斤)，即可顯著改善受 MRSA感染的 C57BL/6小鼠的存活率。後續的耐藥株突變分析和生物信息分析，皆暗示這些抗金黃色葡萄球菌藥物的作用機制可能是通過抑制一個細菌重要的蛋白轉位酵素。鑑於這些小分子藥物高度抑制 MRSA的活性，我們計劃結合彼此在分子生物學、細菌學、藥物化學、結構生物學和模式生物上的專業知識，繼續針對這一重要轉位酵素去開發更有效的抑製劑。我們將首先利用遺傳互補實驗，功能性分析和細菌染色體特定位點突變的方法，進一步分析這一重要轉位酵素在 celecoxib衍生物抗菌活性中的角色。此外，我們亦將建立在試管中的酵素活性測試及利用等溫滴定量熱法和核磁共振光譜法去研究藥物和酵素間的相互作用。此外，我們將利用同源模式計算，用電腦軟體去分析與模擬此一細菌酵素和所找到的小分子藥物間的交互作用。從以上實驗中所收集的資訊，將被用來設計對此一轉位酵素更有效的小分子抑制劑，並且同時在試管中和老鼠體內進行這些新合成試劑的抗菌活性測試。我們預期此一研究計畫將可開發出一類全新的抗菌藥物，用以控制多重抗藥性金黃色葡萄球菌所造成的感染。 <br> Abstract: The emergence and epidemic of multiple-antibiotic resistant Staphylococcus aureus have caused serious therapeutic problems in clinical. Thus, development of novel anti-Staphylococcus agents has become an urgent need for public health. Previously, we have identified several celecoxib derived anti-Staphylococcus agents with potent suppressive activity against S. aureus and methicillin- resistant S. aureus (MRSA) at sub-µg/mL concentrations in growth medium. Moreover, a single intraperitoneal administration of the most potential agent at 30 mg/kg significantly improved the survival of MRSA-infected C57BL/6 mice. Subsequent mutation analysis of resistant isolates and bioinformatics analysis suggested that the action mechanism of these agents might be through inhibition of an essential protein translocase. In light of their high potency in eradicating MRSA, we propose to combine our expertise in molecular biology, bacteriology, medicinal chemistry, structural biology and model organism to continue the development of more potent inhibitor of this essential translocase. We will first utilize genetic complementation assay, functional assay and site-directed mutagenesis of bacterial chromosome to further investigate the role of this essential translocase in the antibacterial activity of the celecoxib derived agents. Also, we will establish the in vitro enzyme activity assay, isothermal titration calorimetry assay and NMR spectroscopy to study the interaction of the drugs and translocase. Moreover, we will utilize homology modeling approach to analysis and simulate the interaction of the translocase and anti-Staphylococcus agents identified. The information collected from assays above will be used to design more potent small-molecule inhibitors of the translocase, and the antibacterial activity of these newly synthesized agents will be tested both in vitro and in vivo. We expect this project will develop a new class of antibacterial drug to control infections caused by multiple-antibiotic resistant S. aureus.耐甲氧西林金黃色葡萄球菌小分子藥物蛋白轉位酵素methicillin-resistant S. aureussmall-molecule agenttranslocase