Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York 10021, USA.
Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Sci Adv. 2024 Mar 15;10(11):eadj6406. doi: 10.1126/sciadv.adj6406.
There is a compelling need to find drugs active against (). 4'-Phosphopantetheinyl transferase (PptT) is an essential enzyme in that has attracted interest as a potential drug target. We optimized a PptT assay, used it to screen 422,740 compounds, and identified raltitrexed, an antineoplastic antimetabolite, as the most potent PptT inhibitor yet reported. While trying unsuccessfully to improve raltitrexed's ability to kill and remove its ability to kill human cells, we learned three lessons that may help others developing antibiotics. First, binding of raltitrexed substantially changed the configuration of the PptT active site, complicating molecular modeling of analogs based on the unliganded crystal structure or the structure of cocrystals with inhibitors of another class. Second, minor changes in the raltitrexed molecule changed its target in from PptT to dihydrofolate reductase (DHFR). Third, the structure-activity relationship for over 800 raltitrexed analogs only became interpretable when we quantified and characterized the compounds' intrabacterial accumulation and transformation.
迫切需要找到针对（）有效的药物。4'-磷酸泛酰巯基乙胺转移酶（PptT）是一种必需酶，已作为潜在的药物靶点引起关注。我们优化了 PptT 测定法，用其筛选了 422,740 种化合物，并鉴定出雷替曲塞（raltitrexed），一种抗肿瘤抗代谢物，是迄今为止报道的最有效的 PptT 抑制剂。在试图提高雷替曲塞杀死（）的能力而又不消除其杀死人类细胞的能力的过程中，我们学到了三条可能有助于其他人开发抗生素的经验教训。首先，雷替曲塞的结合极大地改变了 PptT 活性部位的构象，这使得基于未配位晶体结构或与另一类抑制剂的共晶结构的类似物的分子建模复杂化。其次，雷替曲塞分子的微小变化使其成为二氢叶酸还原酶（DHFR）的靶标。第三，当我们量化和表征了 800 多种雷替曲塞类似物的化合物在细菌内的积累和转化时，其超过 800 种雷替曲塞类似物的结构-活性关系才变得可以解释。
