Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China.
Animal Science and Technology College, Northeast Agricultural University, Harbin 150030, PR China.
Acta Biomater. 2023 Jul 1;164:175-194. doi: 10.1016/j.actbio.2023.04.030. Epub 2023 Apr 24.
Recently, much emphasis has been placed on solving the intrinsic defects of antimicrobial peptides (AMPs), especially their susceptibility to protease digestion for the systemic application of antibacterial biomaterials. Although many strategies have increased the protease stability of AMPs, antimicrobial activity was severely compromised, thereby substantially weakening their therapeutic effect. To address this issue, we introduced hydrophobic group modifications at the N-terminus of proteolysis-resistant AMPs D1 (AArIIlrWrFR) through end-tagging with stretches of natural amino acids (W and I), unnatural amino acid (Nal) and fatty acids. Of these peptides, N1 tagged with a Nal at N-terminus showed the highest selectivity index (GM=19.59), with a 6.73-fold improvement over D1. In addition to potent broad-spectrum antimicrobial activity, N1 also exhibited high antimicrobial stability toward salts, serum and proteases in vitro and ideal biocompatibility and therapeutic efficacy in vivo. Furthermore, N1 killed bacteria through multiple mechanisms, involving disruption of bacterial membranes and inhibition of bacterial energy metabolism. Indeed, appropriate terminal hydrophobicity modification opens up new avenues for developing and applying high-stability peptide-based antibacterial biomaterials. STATEMENT OF SIGNIFICANCE: To improve the potency and stability of proteolysis-resistant antimicrobial peptides (AMPs) without increasing toxicity, we constructed a convenient and tunable platform based on different compositions and lengths of hydrophobic end modifications. By tagging an Nal at the N-terminal, the obtained target compound N1 exhibited strong antimicrobial activity and desirable stability under multifarious environments in vitro (proteases, salts and serum), and also showed favorable biocompatibility and therapeutic efficacy in vivo. Notably, N1 exerted its bactericidal effect by damaging bacterial cell membranes and inhibiting bacterial energy metabolism in a dual mode. The findings provide a potential method for designing or optimizing proteolysis-resistant AMPs thus promoting the development and application of peptide-based antibacterial biomaterial.
最近，人们非常重视解决抗菌肽（AMPs）的内在缺陷，特别是其对蛋白酶消化的敏感性，以实现抗菌生物材料的系统应用。虽然许多策略已经提高了 AMPs 的蛋白酶稳定性，但抗菌活性却严重受损，从而大大降低了它们的治疗效果。为了解决这个问题，我们通过末端标记天然氨基酸（W 和 I）、非天然氨基酸（Nal）和脂肪酸，在蛋白酶抗性 AMP D1（AArIIlrWrFR）的 N 端引入疏水性基团修饰。在这些肽中，在 N 端用 Nal 标记的 N1 表现出最高的选择性指数（GM=19.59），比 D1 提高了 6.73 倍。除了具有强大的广谱抗菌活性外，N1 还表现出对盐、血清和蛋白酶的高体外抗菌稳定性以及理想的生物相容性和体内治疗效果。此外，N1 通过多种机制杀死细菌，包括破坏细菌膜和抑制细菌能量代谢。事实上，适当的末端疏水性修饰为开发和应用高稳定性的基于肽的抗菌生物材料开辟了新途径。
为了在不增加毒性的情况下提高蛋白酶抗性抗菌肽（AMPs）的效力和稳定性，我们构建了一个基于不同组成和长度的疏水性末端修饰的方便且可调的平台。通过在 N 端标记 Nal，得到的目标化合物 N1 在体外多种环境（蛋白酶、盐和血清）下表现出强大的抗菌活性和理想的稳定性，并且在体内也表现出良好的生物相容性和治疗效果。值得注意的是，N1 通过破坏细菌细胞膜和抑制细菌能量代谢的双重模式发挥杀菌作用。这些发现为设计或优化蛋白酶抗性 AMPs 提供了一种潜在的方法，从而促进了基于肽的抗菌生物材料的发展和应用。
