Institute of Biochemistry and Molecular Biology, School of Life Sciences, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
Institute of Food Safety, State Key Laboratory Base of Food Quality and Safety, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Acta Biochim Biophys Sin (Shanghai). 2017 Oct 1;49(10):916-925. doi: 10.1093/abbs/gmx091.
With the increasing emergence of resistant microbes toward conventional antimicrobial agents, there is an urgent need for the development of antimicrobial agents with novel action mode. Antimicrobial peptides (AMPs) are believed to be one kind of ideal alternatives. However, AMPs can be easily degraded by protease, which limited their therapeutic use. In the present study, D-amino acid substitution strategy was employed to enhance the stability of polybia-CP. We investigated the stability of peptides against the degradation of trypsin and chymotrypsin by determining the antimicrobial activity or determining the HPLC profile of peptides after incubation with proteases. Our results showed that both the all D-amino acid derivative (D-CP) and partial D-lysine substitution derivative (D-lys-CP) have an improved stability against trypsin and chymotrypsin. Although D-CP takes left-hand α-helical conformation and D-lys-CP loses some α-helical content, both of the D-amino acid-substituted derivatives maintain their parental peptides' membrane active action mode. In addition, D-lys-CP showed a slight weaker antimicrobial activity than polybia-CP, but the hemolytic activity decreased greatly. These results suggest that D-CP and D-lys-CP can offer strategy to improve the property of AMPs and may be leading compounds for the development of novel antimicrobial agents.
随着传统抗菌药物耐药微生物的不断出现，迫切需要开发具有新型作用模式的抗菌药物。抗菌肽（AMPs）被认为是一种理想的替代品。然而，抗菌肽很容易被蛋白酶降解，这限制了它们的治疗用途。在本研究中，采用 D-氨基酸取代策略来提高聚蜂肽 CP 的稳定性。我们通过测定抗菌活性或在与蛋白酶孵育后测定肽的 HPLC 图谱来研究肽对胰蛋白酶和糜蛋白酶降解的稳定性。结果表明，全 D-氨基酸衍生物（D-CP）和部分 D-赖氨酸取代衍生物（D-lys-CP）对胰蛋白酶和糜蛋白酶的稳定性均有所提高。尽管 D-CP 采取左手α-螺旋构象，D-lys-CP 失去了一些α-螺旋含量，但这两种 D-氨基酸取代衍生物都保持了亲本肽的膜活性作用模式。此外，D-lys-CP 的抗菌活性比聚蜂肽 CP 稍弱，但溶血活性大大降低。这些结果表明，D-CP 和 D-lys-CP 可以为提高 AMPs 的特性提供策略，可能成为开发新型抗菌药物的先导化合物。
