Zhang Xinshuang, Luo Dong, Hu Jie, Wu Kangxiu, Jia Shuyi, Li Xueyi, Huang Songyin, Zhang Houbing, Kim Dokyun, Hong Yuzhi, Zhao Liping, Xiong Menghua, Bao Yan
School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou, 511442, PR China; National Engineering Research Centre for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, 510006, PR China.
Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicine, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, PR China; Department of Clinical Laboratory, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, PR China.
Biomaterials. 2025 Nov;322:123392. doi: 10.1016/j.biomaterials.2025.123392. Epub 2025 May 6.
The distinct phospholipid compositions of bacterial and mammalian cell membranes offer a promising target for the development of antimicrobial peptides (AMPs). However, distinguishing between the similarly charged anionic phospholipids-bacterial phosphatidylglycerol (PG) and mammalian phosphatidylserine (PS)-poses a significant challenge. Here we introduce a competitive inhibition strategy that leverages host-guest interactions to enable AMPs to selectively recognize PG without engaging with PS. After analyzing the binding interactions of various radially amphiphilic AMPs (RAPs), host molecules, and phospholipids, we discovered that a RAP, named C6HO, exhibited a higher affinity for cucurbit[7]uril (CB[7]) compared to PS, yet a lower affinity than for PG. Consequently, CB[7] functions as a competitive inhibitor: by forming a complex with C6HO upon simple mixing, it prevents C6HO from interacting with PS. Notably, PG can outcompete CB[7] for binding to C6HO within the complex, leading to the aggregation of PG molecules and the subsequent disruption of membranes rich in PG. Furthermore, the competitive inhibitor CB[7] effectively neutralizes C6HO's cytotoxic effects on mammalian cells while preserving the antimicrobial potency of C6HO. In vivo experiments in a subcutaneous infection model demonstrated that CB[7] reduced both systemic and local toxicity of C6HO without compromising its antimicrobial efficacy. Our study presents a strategy for the specific recognition of bacterial phospholipids and the design of highly selective AMPs.
细菌和哺乳动物细胞膜独特的磷脂组成，为抗菌肽（AMPs）的开发提供了一个有前景的靶点。然而，区分电荷相似的阴离子磷脂——细菌磷脂酰甘油（PG）和哺乳动物磷脂酰丝氨酸（PS）——是一项重大挑战。在此，我们引入一种竞争性抑制策略，利用主客体相互作用使AMPs能够选择性识别PG而不与PS结合。在分析了各种径向两亲性AMPs（RAPs）、主体分子和磷脂的结合相互作用后，我们发现一种名为C6HO的RAP与葫芦[7]脲（CB[7]）的亲和力高于PS，但低于PG。因此，CB[7]起到竞争性抑制剂的作用：通过简单混合后与C6HO形成复合物，它阻止C6HO与PS相互作用。值得注意的是，PG能够在复合物中竞争取代CB[7]与C6HO的结合，导致PG分子聚集，进而破坏富含PG的膜。此外，竞争性抑制剂CB[7]有效中和了C6HO对哺乳动物细胞的细胞毒性作用，同时保留了C6HO的抗菌效力。皮下感染模型的体内实验表明，CB[7]降低了C6HO的全身和局部毒性，同时不影响其抗菌效果。我们的研究提出了一种特异性识别细菌磷脂和设计高选择性AMPs的策略。
