Engineering Monobactam Biosynthesis towards the Generation of Novel β-Lactam Antibiotics

工程单菌素生物合成以产生新型β-内酰胺抗生素

• 批准号: 492438365
• 负责人: Dr. Lukas Kahlert
• 金额: --
• 依托单位: Department of Chemistry
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/492438365?language=en
• 关键词: Engineering; Monobactam; Biosynthesis; towards; Generation

β-lactam antibiotics are included in the WHO model list of essential medicines and represent an indispensible tool for the treatment of bacterial infections. Yet, emerging bacterial resistance constitutes a serious threat towards the medical community and calls for the development of new β-lactam derivatives. Monobactams , a subclass of β-lactam antibiotics, stand out due to their intrinsic stability against metallo-β-lactamases that render most of the clinically used β-lactam antibiotics ineffective. All monobactams (approved or in clinical studies) are manufactured completely synthetic. The recent discovery of the first bacterial biosynthetic gene cluster that is responsible for the production of the monobactam sulfazecin offers a very promising target towards the generation of novel monobactams through bioengineering and semi-synthetic chemistry. The backbone of sulfazecin is made from three amino acid building blocks by two multi-domain enzymes and further modified to yield the final β-lactam product. Preliminary studies show that the biosynthetic machinery is also capable to process a structural analog of the third amino acid building block, producing a sulfacezin analog that features an additional methyl-substituent at the β-lactam core (from synthetic monobactams it is known that substitution at this position dramatically increases hydrolytic stability). Promiscuity of each enzyme of the biosynthetic machinery towards this structural substrate analog harbours a tremendous potential towards the generation of novel monobactams by green chemistry (fermentation). Structure guided mutations within defined parts of the involved biosynthetic enzymes are purposed to extend and manipulate the spectrum of incorporated building blocks, yielding the desired monobactam products. Subsequent chemical side chain modification is intended to increase the structural variety even more. The substrate promiscuity/specificity of the mutant enzymes can be either assessed in vivo or in vitro. Bioassays will evaluated potential of novel monobactams.

β-内酰胺抗生素被列入世卫组织基本药物示范清单，是治疗细菌感染不可或缺的工具。然而，新出现的细菌耐药性对医学界构成了严重威胁，并要求开发新的β-内酰胺衍生物。单环内酰胺类是β-内酰胺抗生素的一个亚类，由于其对金属-β-内酰胺酶的内在稳定性而脱颖而出，金属-β-内酰胺酶使大多数临床使用的β-内酰胺抗生素无效。所有单环内酰胺类（已批准或在临床研究中）都是完全合成的。最近发现的第一个细菌生物合成基因簇，负责生产的monobactam磺胺菌素提供了一个非常有前途的目标，通过生物工程和半合成化学产生新的monobactams。磺胺菌素的骨架由两种多结构域酶的三个氨基酸结构单元制成，并进一步修饰以产生最终的β-内酰胺产物。初步研究表明，生物合成机制也能够处理第三个氨基酸结构单元的结构类似物，产生在β-内酰胺核心处具有额外甲基取代基的磺酰肼类似物（从合成单环内酰胺中已知，在该位置处的取代显著增加水解稳定性）。生物合成机制的每种酶对这种结构底物类似物的混杂性对通过绿色化学（发酵）产生新型单环内酰胺类具有巨大的潜力。在所涉及的生物合成酶的限定部分内的结构引导的突变旨在扩展和操纵掺入的结构单元的谱，从而产生所需的单环内酰胺产物。随后的化学侧链修饰旨在进一步增加结构多样性。突变酶的底物混杂性/特异性可以在体内或体外评估。生物测定将评估新型单环内酰胺的潜力。