Structural and mechanistic investigation of the Cytochrome P450 enzymes in vancomycin biosynthesis: potential biocatalysts for the development of new antibiotics

万古霉素家族的抗生素是具有抗革兰氏阳性细菌活性的糖肽，被用作治疗某些细菌感染的最后手段。它们通过与细胞壁前体形成复合体来发挥作用，从而抑制细菌细胞壁的生物合成。然而，它们的使用受到越来越多的耐药性问题的限制：出现细菌菌株时，前体被修饰，不再与万古霉素紧密结合。如果能在短时间内生产出新的万古霉素类似物，将具有重大的医学意义。这一点受到万古霉素化学合成的复杂性的阻碍，特别是在体内由细胞色素P450(Oxy)酶执行的酚类交联反应。氧合酶的作用机制本身就具有特殊的科学价值，将在本项目中使用结构和生化方法相结合的方法进行详细研究。这些实验的结果将回答有关底物识别和氧化的核心问题。它们还将为替代和快速合成万古霉素类似物提供基础，使用合成肽作为起点，但使用氧基酶进行关键的最终交联反应。这项工作的一个可能的扩展将是重新设计万古霉素生物合成基因簇的元件，使万古霉素类似物的整个合成能够在体内合适的生物体中进行。

Antibiotics of the vancomycin family are glycopeptides with activity against Gram-positive bacteria, and are used as a last resort in the treatment of certain bacterial infections. They work by forming a complex with a cell-wall precursor, thus inhibiting bacterial cell wall biosynthesis. Their use is however restricted by the increasing problem of resistance: bacterial strains arise in which the precursor is modified and no longer tightly binds to vancomycin. It would be of great medical significance if new vancomycin analogues could be produced at short notice. This is hindered by the complexity of the chemical synthesis of vancomycin, in particular the phenolic crosslinking reactions which, in vivo, are performed by Cytochrome P450 (Oxy) enzymes. The mechanisms of action of the Oxy enzymes are of exceptional scientific interest in their own right, and will be studied in detail in this project using a combination of structural and biochemical approaches. The results from these experiments will answer central questions concerning substrate recognition and oxidation. They will also provide the basis for an alternative and rapid synthesis of vancomycin analogues, using synthetic peptides as the starting point but Oxy enzymes for the crucial final crosslinking reactions. A possible extension of this work will be to re-engineer elements of the vancomycin biosynthetic gene cluster to allow the entire synthesis of vancomycin analogues to be performed in suitable organisms in vivo.