Enzymatic Synthesis of the key Intermediates in Peptidoglycan Biosynthesis and the Cell Wall Engineering in Living Bacteria

• Main Authors: Chia-Feng Hsieh, 謝嘉峰
• Other Authors: Chun-Hung Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/28957589467556384919

碩士 === 國立臺灣大學 === 生化科學研究所 === 95 === Abstract In the past few decades when antibiotics have been extensively in therapeutic use, the antibiotics resistances have emerged. It is important to find out new and broad-range antibiotics substitutes. There are many targets for antibiotics to work and we lay a special emphasis on the enzymes involved in bacteria cell wall biosynthesis. UDP-MurNAc-pentapeptide, Lipid I and Lipid II are the key intermediates in peptidoglycan biosynthesis, are the targets of our large scale synthesis. There are ten enzymes in this process including MraY and MurG that are located in the membrane. UDP-MurNAc-pentapeptide and Lipid I are their substrates respectively. We establish an efficient method to prepare UDP-MurNAc-pentapeptide including DAP and Lys form, Lipid I and their derivatives with a fluorescent group like dansyl and FITC. Furthermore, enzymatic methods were then studied to incorperate lipid chains of different length for preparing Lipid I and Lipid II analogues. Furthermore, we use the fluorescent group labeled peptidoglycan precursors FITC-UDP-MurNAc-pentapeptide to develop a method for the chemical engineering of the bacterial cell surface. It will allow a large variety of molecular specimens to be displayed, leading to a wide range of applications, such as in discovery of novel drugs or vaccines.