近幾年由於抗藥性細菌持續的威脅著人類的健康，醫療上急切需要科學家發展出新一代的抗生素。在現今社會中，萬古黴素以及乳酸鏈球菌素這些天然抗生素被證實擁有良好的抗菌活性並且以肽聚醣的片段為標靶。本篇論文，設計了一些肽聚醣的分子像是三胜肽 (tripeptide)以及glycopyrophosphates經由適當的條件連結在載體上形成化學探針，更進一步的利用對肽聚醣的片段有作用的已知抗生素來探討這些化學探針。
利用萬古黴素以及乳酸鏈球菌素與肽聚醣片段的作用，當成實驗的範本用以證實如何有效的運用此探針以及實驗的流程，這些化學探針結合了分析的儀器之後更能夠成為一個好的策略，使得這項策略能用在探討新的肽聚醣的結合物並且縮減了傳統純化的過程。

The accelerating appearance of drug-resistant bacteria results in a serious threat to human health. As a result, it is urgent for scientist to search for new effective antibiotics.
Currently, some naturally occurring antibacterial agents, such as vancomycin and nisin typed molecules, have been demonstrated not only to show potent antibacterial activity, but also to target peptidoglycan (PG) fragments or peptidoglycan precursors.
In this work, we designed several PG molecules such as the tripeptide and glycopyrophophates to immobilize on a solid-support through a proper linker and conjugation conditions. To approve our concept, these PG-immobilized resins were interacted with natural binders, including vancomycin and crude nisin, to investigate how to enrich or identify PG-binders from crude mixture. Our probes with the assistance of analytical equipment, such as imaging mass spectrometry (IMS) and/or high-performance liquid chromatography (HPLC), become a powerful tool, allowing us not only to explore new PG binders but also to simplify traditional purification procedures.

1. Donadio, S.; Maffioli, S.; Monciardini, P.; Sosio, M.; Jabes, D., Antibiotic discovery in the twenty-first century: current trends and future perspectives. J. Antibiot. 2010, 63, 423-430.
2. Hamburger, J. B.; Hoertz, A. J.; Lee, A.; Senturia, R. J.; McCafferty, D. G.; Loll, P. J., A crystal structure of a dimer of the antibiotic ramoplanin illustrates membrane positioning and a potential Lipid II docking interface. Proc. Natl. Acad. Sci. U.S.A. 2009, 106, 13759-13764.
3. Martin, N. I.; Breukink, E., The expanding role of lipid II as a target for lantibiotics. Future Microbiol. 2007, 2, 513-525.
4. Liu, H.; Ritter, T. K.; Sadamoto, R.; Sears, P. S.; Wu, M.; Wong, C.-H., Acceptor Specificity and Inhibition of the Bacterial Cell-Wall Glycosyltransferase MurG. ChemBioChem 2003, 4, 603-609.
5. Christ, K.; Wiedemann, I.; Bakowsky, U.; Sahl, H.-G.; Bendas, G., The role of lipid II in membrane binding of and pore formation by nisin analyzed by two combined biosensor techniques. Biochim. Biophys. Acta. 2007, 1768, 694-704.
6. Breukink, E.; de Kruijff, B., Lipid II as a target for antibiotics. Nat. Rev. Drug Discov. 2006, 5, 321-323.
7. Vollmerhaus, P. J.; Breukink, E.; Heck, A. J. R., Getting Closer to the Real Bacterial Cell Wall Target: Biomolecular Interactions of Water-Soluble Lipid II with Glycopeptide Antibiotics. Chem. Eur. J. 2003, 9, 1556-1565.
8. Healy, V. L.; Lessard, I. A. D.; Roper, D. I.; Knox, J. R.; Walsh, C. T., Vancomycin resistance in enterococci: reprogramming of the D-Ala–D-Ala ligases in bacterial peptidoglycan biosynthesis. Chem. Biol. 2000, 7, R109-R119.
9. Walsh, C. T.; Fisher, S. L.; Park, I. S.; Prahalad, M.; Wu, Z., Bacterial resistance to vancomycin: five genes and one missing hydrogen bond tell the story. Chem. Biol.1996, 3, 21-28.
10. Corti, A.; Cassani, G., Synthesis and characterization of D-Alanyl-D-Alanine-Agarose. Appl. Biochem. Biotechnol. 1985, 11, 101-109.
11. Chen, Y.-Y.; He, W.-Y.; Wu, Y.; Niu, C.-Q.; Liu, G., Dynamic selection of novel vancomycin N-terminal derivatives by resin-bound reversed D-Ala-D-Ala. J. Comb. Chem. 2008, 10, 914-922.
12. Boger, D. L., Vancomycin, teicoplanin, and ramoplanin: Synthetic and mechanistic studies. Med. Res. Rev. 2001, 21, 356-381.
13. Svetitsky, S.; Leibovici, L.; Paul, M., Comparative efficacy and safety of vancomycin versus teicoplanin: systematic review and meta-analysis. Antimicrob. Agents Chemother. 2009, 53, 4069-4079.
14. Hu, Y.; Helm, J. S.; Chen, L.; Ye, X.-Y.; Walker, S., Ramoplanin inhibits bacterial transglycosylases by binding as a dimer to lipid II. J. Am. Chem. Soc. 2003, 125, 8736-8737.
15. Cudic, P.; Kranz, J. K.; Behenna, D. C.; Kruger, R. G.; Tadesse, H.; Wand, A. J.; Veklich, Y. I.; Weisel, J. W.; McCafferty, D. G., Complexation of peptidoglycan intermediates by the lipoglycodepsipeptide antibiotic ramoplanin: Minimal structural requirements for intermolecular complexation and fibril formation. Proc. Natl. Acad. Sci. 2002, 99, 7384-7389.
16. Willey, J. M.; van der Donk, W. A., Lantibiotics: Peptides of diverse structure and function. Annu. Rev. Microbio. 2007, 61, 477-501.
17. Hsu, S.-T. D.; Breukink, E.; Tischenko, E.; Lutters, M. A. G.; de Kruijff, B.; Kaptein, R.; Bonvin, A. M. J. J.; van Nuland, N. A. J., The nisin-lipid II complex reveals a pyrophosphate cage that provides a blueprint for novel antibiotics. Nat. Struct. Mol. Biol. 2004, 11, 963-967.
18. Mantovani, H. C.; Hu, H.; Worobo, R. W.; Russell, J. B., Bovicin HC5, a bacteriocin from Streptococcus bovis HC5. Microbiology 2002, 148, 3347-3352.
19. Paiva, A. D.; Breukink, E.; Mantovani, H. C., Role of Lipid II and membrane thickness in the mechanism of action of the lantibiotic bovicin HC5. Antimicrob. Agents Chemother. 2011, 55, 5284-5293.
20. Higg, R. E.; Zhen, E.; Hale, J. E.; Saxena, C., Small-molecule affinity chromatography coupled mass spectrometry for drug target deconvolution. Expert. Opin. Biol. Ther. 2009, 4, 701-714.
21. Stembera, K.; Buchynskyy, A.; Vogel, S.; Knoll, D.; Osman, A. A.; Ayala, J. A.; Welzel, P., Moenomycin-mediated affinity purification of penicillin-binding protein 1b. ChemBioChem 2002, 3, 332-340.
22. Yu-Liang, Y.; Yuquan, X.; Paul, S.; Pieter, C. D., Translating metabolic exchange with imaging mass spectrometry. Nat. Chem. Biol. 2009, 5, 885-887.
23. Singh, M. P.; Petersen, P. J.; Weiss, W. J.; Janso, J. E.; Luckman, S. W.; Lenoy, E. B.; Bradford, P. A.; Testa, R. T.; Greenstein, M., Mannopeptimycins, New cyclic glycopeptide antibiotics produced by streptomyces hygroscopicus LL-AC98: antibacterial and mechanistic activities. Antimicrob. Agents Chemother. 2003, 47, 62-69.
24. Seng, P.; Rolain, J.-M.; Fournier, P. E.; La Scola, B.; Drancourt, M.; Raoult, D., MALDI-TOF-mass spectrometry applications in clinical microbiology. Future Microbiol. 2010, 5, 1733-1754.
25. Park, J. T., Uridine-5'-pyrophosphate Derivatives: I. Isolation From Staphylococcus aureus. J. Biol. Chem. 1952, 194, 877-884.
26. Chen, K.-T.; Kuan, Y.-C.; Fu, W.-C.; Liang, P.-H.; Cheng, T.-J. R.; Wong, C.-H.; Cheng, W.-C., Rapid preparation of mycobacterium N-Glycolyl Lipid I and Lipid II derivatives: A biocatalytic approach. Chem. Eur. J. 2013, 19, 834-838.
27. Liu, C.-Y.; Guo, C.-W.; Chang, Y.-F.; Wang, J.-T.; Shih, H.-W.; Hsu, Y.-F.; Chen, C.-W.; Chen, S.-K.; Wang, Y.-C.; Cheng, T.-J. R.; Ma, C.; Wong, C.-H.; Fang, J.-M.; Cheng, W.-C., Synthesis and evaluation of a new fluorescent transglycosylase substrate: Lipid II-based molecule possessing a dansyl-C20 polyprenyl moiety. Org. Lett. 2010, 12, 1608-1611.
28. (a) Molinari, H.; Pastore, A.; Lian, L. Y.; Hawkes, G. E.; Sales, K., Structure of vancomycin and a vancomycin/D-Ala-D-Ala complex in solution. Biochemistry 1990, 29, 2271-2277; (b) Sheldrick, G. M.; Jones, P. G.; Kennard, O.; Williams, D. H.; Smith, G. A., Structure of vancomycin and its complex with acetyl-D-alanyl-D-alanine. Nature 1978, 271, 223-225.
29. Mota-Meira, M.; Lapointe, G.; Lacroix, C.; Lavoie, M. C., MICs of mutacin B-Ny266, nisin A, vancomycin, and oxacillin against bacterial pathogens. Antimicrobl. Agents Chemother. 2000, 44, 24-29.
30. Gross, E.; Morell, J. L., Presence of dehydroalanine in the antibiotic nisin and its relation to activity. J. Amer. Chem. Soc. 1967, 89, 2791-2792.
31. Rollema, H. S.; Metzger, J. W.; Both, P.; Kuipers, O. P.; Siezen, R. J., Structure and biological activity of chemically modified nisin a species. Eur. J. Biochem. 1996, 241, 716-722.
32. Lavanant, H.; Derrick, P. J.; Heck, A. J. R.; Mellon, F. A., Analysis of nisin A and some of its variants using fourier transform ion cyclotron resonance mass spectrometry. Anal. Biochem. 1998, 255, 74-89.
33. Yang, R.; Johnson, M. C.; Ray, B., Novel method to extract large amounts of bacteriocins from lactic acid bacteria. Appl. Environ. Microbiol. 1992, 58, 3355-3359.
34. Likozar, B.; Senica, D.; Pavko, A., Comparison of adsorption equilibrium and kinetic models for a case study of pharmaceutical active ingredient adsorption from fermentation broths: parameter determination, simulation, sensitivity analysis and optimization. Braz. J. Chem. Eng. 2012, 29, 635-652.
35. Walker, S.; Chen, L.; Hu, Y.; Rew, Y.; Shin, D.; Boger, D. L., Chemistry and biology of ramoplanin: A lipoglycodepsipeptide with potent antibiotic activity. Chem. Rev. 2005, 105, 449-476.
36. Giancarlo L,; Angelo B,; Piero A., Method for selectively increasing the ratio of single major components of antibiotic A/16686 complex. U.S. Patent 5,925,550, Jul. 20, 1999.
37. Yun B. S.; Hidaka T.; Furihata K.; Seto H., Microbial metabolites with tipA promoter
inducing activity. II. Geninthiocin, a novel thiopeptide produced by Streptomyces sp. DD84. J. Antibiot.1994, 47, 969-975.
38. Sajid, I.; Shaaban, K.A.; Frauendorf, H.; Hasnain, S.; Laatsch, H., Val-Geninthiocin:
Structure elucidation and MSn fragmentation of thiopeptide antibiotics produced by Streptomyces sp. RSF18. Naturforsch., B: Chem. Sci. 2008, 10, 1223-1230.