5月27日，德国波恩大学科学家报告说，他们与丹麦和荷兰科学家合作发现了一种新型抗菌肽——菌丝霉素的抗菌机理。科学家认为这种抗菌肽有望在新型抗菌素研发中发挥主导作用。
菌丝霉素是丹麦生物技术公司数年前从真菌中分离出的一种防御素。防御素是存在于动物和高等植物中的一类富含半胱氨酸的天然抗菌肽，它们对多种微生物均具有较强的防御能力，因此，防御素也是目前颇具吸引力的一类新型候选抗菌药物。
科学家们此次发现，菌丝霉素与细菌细胞膜形成的前体物质Lipid Ⅱ具有很强的亲和性，可以通过与Lipid Ⅱ结合阻止病菌细胞膜的形成，从而阻止病菌繁殖。
德国科学家指出，菌丝霉素的抗菌方式类似于现在广泛使用的药物万古霉素。后者20年来在对抗具有顽固抗药性的耐甲氧西林金黄色葡萄球菌领域发挥了重要作用。但是，近年来越来越多的病菌对万古霉素也产生了抗药性，对菌丝霉素则依然敏感，因而菌丝霉素成了研制新型抗菌药的希望之星。
但是德国科学家同时指出，菌丝霉素也不能一劳永逸地解决病菌抗药性问题。病菌逐步变异，对新药物产生抗药性只是时间问题。人类与病菌之间永远存在“军备竞赛”。(生物谷Bioon.com)
生物谷推荐原文出处：
Science DOI: 10.1126/science.1185723
Plectasin, a Fungal Defensin, Targets the Bacterial Cell Wall Precursor Lipid II
Tanja Schneider,1 Thomas Kruse,2 Reinhard Wimmer,3 Imke Wiedemann,1 Vera Sass,1 Ulrike Pag,1 Andrea Jansen,1 Allan K. Nielsen,4 Per H. Mygind,4 Dorotea S. Raventós,4 S?ren Neve,4 Birthe Ravn,4 Alexandre M. J. J. Bonvin,5 Leonardo De Maria,4 Anders S. Andersen,2,4 Lora K. Gammelgaard,4 Hans-Georg Sahl,1 Hans-Henrik Kristensen4,*
Host defense peptides such as defensins are components of innate immunity and have retained antibiotic activity throughout evolution. Their activity is thought to be due to amphipathic structures, which enable binding and disruption of microbial cytoplasmic membranes. Contrary to this, we show that plectasin, a fungal defensin, acts by directly binding the bacterial cell-wall precursor Lipid II. A wide range of genetic and biochemical approaches identify cell-wall biosynthesis as the pathway targeted by plectasin. In vitro assays for cell-wall synthesis identified Lipid II as the specific cellular target. Consistently, binding studies confirmed the formation of an equimolar stoichiometric complex between Lipid II and plectasin. Furthermore, key residues in plectasin involved in complex formation were identified using nuclear magnetic resonance spectroscopy and computational modeling.
1 Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology, and Parasitology, University of Bonn, D-53115 Bonn, Germany.
2 Statens Serum Institut, 2300 Copenhagen S, Denmark.
3 Department of Biotechnology, Chemistry, and Environmental Engineering, Aalborg University, DK-9000 Aalborg, Denmark.
4 Novozymes AS, DK-2880 Bagsvaerd, Denmark.
5 Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, Netherlands.
