Nature has evolved biosynthetic pathways to molecules possessing reactive warheads that inspired the development of many therapeutic agents, including penicillin antibiotics. Peptides armed with electrophilic warheads have proven to be particularly effective covalent inhibitors, providing essential antimicrobial, antiviral and anticancer agents. Here we provide a full characterization of the pathways that nature deploys to assemble peptides with β-lactone warheads, which are potent proteasome inhibitors with promising anticancer activity. Warhead assembly involves a three-step cryptic methylation sequence, which is likely required to reduce unfavorable electrostatic interactions during the sterically demanding β-lactonization. Amide-bond synthetase and adenosine triphosphate (ATP)-grasp enzymes couple amino acids to the β-lactone warhead, generating the bioactive peptide products. After reconstituting the entire pathway to β-lactone peptides in vitro, we go on to deliver a diverse range of analogs through enzymatic cascade reactions. Our approach is more efficient and cleaner than the synthetic methods currently used to produce clinically important warhead-containing peptides.

大自然已经进化出了具有反应弹头的分子的生物合成途径，这激发了包括青霉素抗生素在内的许多治疗剂的开发。携带亲电弹头的肽已被证明是特别有效的共价抑制剂，可提供必要的抗菌、抗病毒和抗癌药物。在这里，我们提供了自然界利用β-内酯弹头组装肽的途径的完整表征，β-内酯弹头是有效的蛋白酶体抑制剂，具有良好的抗癌活性。弹头组装涉及三步神秘甲基化序列，这可能是减少空间要求高的β-内酯化过程中不利的静电相互作用所必需的。酰胺键合成酶和三磷酸腺苷 (ATP) 抓取酶将氨基酸与 β-内酯弹头偶联，生成生物活性肽产物。在体外重建 β-内酯肽的整个途径后，我们继续通过酶促级联反应提供多种类似物。我们的方法比目前用于生产临床上重要的含弹头肽的合成方法更有效、更清洁。