Centre of New Technologies, University of Warsaw, Warsaw, Poland.
Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland.
Sci Rep. 2023 Sep 8;13(1):14826. doi: 10.1038/s41598-023-38745-y.
Given the widespread demand for novel antibacterial agents, we modified a cell-penetrating peptide (KFF)K to transform it into an antibacterial peptide. Namely, we inserted a hydrocarbon staple into the (KFF)K sequence to induce and stabilize its membrane-active secondary structure. The staples were introduced at two positions, (KFF)K[5-9] and (KFF)K[2-6], to retain the initial amphipathic character of the unstapled peptide. The stapled analogues are protease resistant contrary to (KFF)K; 90% of the stapled (KFF)K[5-9] peptide remained undigested after incubation in chymotrypsin solution. The stapled peptides showed antibacterial activity (with minimal inhibitory concentrations in the range of 2-16 µM) against various Gram-positive and Gram-negative strains, contrary to unmodified (KFF)K, which had no antibacterial effect against any strain at concentrations up to 32 µM. Also, both stapled peptides adopted an α-helical structure in the buffer and micellar environment, contrary to a mostly undefined structure of the unstapled (KFF)K in the buffer. We found that the antibacterial activity of (KFF)K analogues is related to their disruptive effect on cell membranes and we showed that by stapling this cell-penetrating peptide, we can induce its antibacterial character.
鉴于对新型抗菌剂的广泛需求，我们对细胞穿透肽 (KFF)K 进行了修饰，将其转化为抗菌肽。也就是说，我们在 (KFF)K 序列中插入了一个烃链 staples，以诱导并稳定其具有膜活性的二级结构。 staples 被引入两个位置，(KFF)K[5-9]和 (KFF)K[2-6]，以保留未 stapled 肽的初始两亲性特征。与 (KFF)K 相比， stapled 类似物具有抗蛋白酶性；在胰凝乳蛋白酶溶液中孵育后，90%的 stapled (KFF)K[5-9]肽保持未消化。与未修饰的 (KFF)K 相反， stapled 肽对各种革兰氏阳性和革兰氏阴性菌株均具有抗菌活性（最小抑菌浓度范围为 2-16 μM），而未修饰的 (KFF)K 对任何菌株的浓度高达 32 μM 均无抗菌作用。此外，两种 stapled 肽在缓冲液和胶束环境中均采用 α-螺旋结构，而未 stapled (KFF)K 在缓冲液中则主要呈现无定形结构。我们发现 (KFF)K 类似物的抗菌活性与其对细胞膜的破坏作用有关，我们通过 stapling 这种细胞穿透肽，诱导其具有抗菌特性。
