Hao Gang, Le Guo-Wei, Shi Yong-Hui, Ma Dan-Ya
College of Life Science and Technology, Southwest University for Nationalities, Chengdu 610041, China.
Yao Xue Xue Bao. 2013 Mar;48(3):366-71.
A novel peptide, named BF2-X, was designed based on the structure-activity analysis of an analogue of Buforin II, named BF2-A. The BF2-X was a hybrid peptide containing the N-terminal residues 5 to 13 of BF2-A and three repeats of the C-terminal regular alpha-helical motif RLLR, and the residues 8 valine were replaced by leucine. The results of bioinformatics analysis had showed that compared with BF2-A, the helicity, positive charge, hydrophobicity rate and C-terminal amphipathy of BF2-X had remarkably enhanced. Both peptides showed a random coil structure in an aqueous solution, while displaying a typical alpha-helical structure in 50% trifluoroethanol solution (a membrane mimic condition). BF2-X exhibited higher alpha-helical contents than BF2-A in hydrophobic environment. BF2-X displayed potent antimicrobial activities against a broad spectrum of microorganisms. And BF2-X showed stronger antimicrobial activities against bacteria tested than parent peptide BF2-A. These results suggest that the alpha-helical content was directly correlated with the enhanced antibacterial activity. Both peptides had no hemolytic action on mouse erythrocyte.
基于蟾蜍灵II类似物BF2-A的结构活性分析，设计了一种名为BF2-X的新型肽。BF2-X是一种杂合肽，包含BF2-A的N端5至13位残基以及C端规则α-螺旋基序RLLR的三个重复序列，且8个缬氨酸残基被亮氨酸取代。生物信息学分析结果表明，与BF2-A相比，BF2-X的螺旋度、正电荷、疏水率和C端两亲性显著增强。两种肽在水溶液中均呈现无规卷曲结构，而在50%三氟乙醇溶液（一种膜模拟条件）中呈现典型的α-螺旋结构。在疏水环境中，BF2-X比BF2-A表现出更高的α-螺旋含量。BF2-X对多种微生物具有强大的抗菌活性。并且BF2-X对所测试细菌的抗菌活性比亲本肽BF2-A更强。这些结果表明，α-螺旋含量与增强的抗菌活性直接相关。两种肽对小鼠红细胞均无溶血作用。
