Nuclease activity gives an edge to host-defense peptide piscidin 3 over piscidin 1, rendering it more effective against persisters and biofilms.
Nuclease activity gives an edge to host-defense peptide piscidin 3 over piscidin 1, rendering it more effective against persisters and biofilms.
复制标题
DOI：
10.1111/febs.14263
复制
发表时间：
2017-11
期刊：
影响因子：
--
通讯作者：
Cotten ML
中科院分区：
文献类型：
--
作者：
Libardo MDJ;Bahar AA;Ma B;Fu R;McCormick LE;Zhao J;McCallum SA;Nussinov R;Ren D;Angeles-Boza AM;Cotten ML
宿主防御肽 (HDP) 具有经过进化测试的针对危及生命的病原体的效力。虽然 piscidin 1 (p1) 和 piscidin 3 (p3) 是同源且有效的鱼类 HDP，但只有 p1 具有强膜溶解性。在这里，我们假设另一种机制赋予 p3 强大的效力。我们证明，两种肽的 N 末端协调 Cu2+ 和 p3-Cu 以与游离 Cu2+ 相当的速度切割分离的 DNA，但明显快于 p1-Cu。对于浮游细菌，p1 更具抗菌性，但只有 p3 具有铜依赖性 DNA 切割功能。在生物膜和存留细胞上，p3-Cu 比 p1-Cu 更活跃，与更强的肽诱导的 DNA 损伤相称。分子动力学和核磁共振表明，与 p1 相比，p3 存在更多的 DNA-肽相互作用，并且肽采用同时准备金属和 DNA 结合的构象。这些结果产生了几个重要的结论。首先，不能假设同源 HDP 具有相同的机制，因为 p1 和 p3 通过膜和 DNA 破坏效应的不同相对贡献来根除细菌。其次，p1 和 p3 的核酸酶和膜活性表明，天然存在的 HDP 不仅会造成物理化学损伤，还会造成共价损伤。第三，强核酸酶活性对于生物膜和存留细胞的根除至关重要，如 p3 所示，同源物对细菌更具特异性，并且在血管化组织中表达更多。第四，p3 结合了多种物理化学特性（例如，氨基末端铜和镍结合基序；大量精氨酸；中等疏水性），这些特性赋予低膜溶解效应、强大的铜清除能力、与 DNA 的强相互作用以及快速的核酸酶活性。这些新知识可以帮助设计针对难以治疗的持久细胞和生物膜的新型疗法。
Host-defense peptides (HDPs) feature evolution-tested potency against life-threatening pathogens. While piscidin 1 (p1) and piscidin 3 (p3) are homologous and potent fish HDPs, only p1 is strongly membranolytic. Here, we hypothesize that another mechanism imparts p3 strong potency. We demonstrate that the N-termini of both peptides coordinate Cu2+ and p3-Cu cleaves isolated DNA at a rate on par with free Cu2+ but significantly faster than p1-Cu. On planktonic bacteria, p1 is more antimicrobial but only p3 features copper-dependent DNA cleavage. On biofilms and persister cells, p3-Cu is more active than p1-Cu, commensurate with stronger peptide-induced DNA damage. Molecular dynamics and NMR show that more DNA-peptide interactions exist with p3 than p1, and the peptides adopt conformations simultaneously poised for metal- and DNA-binding. These results generate several important conclusions. First, homologous HDPs cannot be assumed to have identical mechanisms since p1 and p3 eradicate bacteria through distinct relative contributions of membrane and DNA-disruptive effects. Second, the nuclease and membrane activities of p1 and p3 show that naturally occurring HDPs can inflict not only physicochemical but also covalent damage. Third, strong nuclease activity is essential for biofilm and persister cell eradication, as shown by p3, the homolog more specific toward bacteria and more expressed in vascularized tissues. Fourth, p3 combines several physicochemical properties (e.g., Amino Terminal Copper and Nickel binding motif; numerous arginines; moderate hydrophobicity) that confer low membranolytic effects, robust copper-scavenging capability, strong interactions with DNA, and fast nuclease activity. This new knowledge could help design novel therapeutics active against hard-to-treat persister cells and biofilms.