Laboratorio de Espectroscopia Atómica y Molecular (LEAM), Escuela de Química, Universidad Industrial de Santander, Parque Tecnológico Guatiguará, Piedecuesta, 681012, Colombia.
Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Escuela de Bacteriología, Universidad Industrial de Santander, Bucaramanga, 680002, Colombia.
Probiotics Antimicrob Proteins. 2016 Sep;8(3):134-40. doi: 10.1007/s12602-016-9219-9.
In this work, we performed the rational design of a cationic antimicrobial peptide, GIBIMPY4, using the software DEPRAMPs developed at the GIBIM research group. GIBIMPY4 has a length of 17 amino acids, it is amphipathic, its structure is α-helix and it has a net charge of (+5). Solid-phase peptide synthesis was performed using the Fmoc strategy in acid medium. The primary structure was confirmed by MALDI-TOF mass spectrometry. The antimicrobial activity of the peptide was evaluated by broth microdilution method by measuring optical density in 96-well microplates. The minimal inhibitory concentration of GIBIMPY4 to kill 50 % of the bacterial cells (MIC50) was 6.20 ± 0.02 µM for MRSA and 4.55 ± 0.02 µM for E. coli O157:H7, while also reporting a bacteriostatic effect for the later. GIBIMPY4 activity was sensitive to salt concentration in E. coli but insignificant effect in its activity against MRSA. The peptide seems to be a broad-spectrum antimicrobial agent based on the results against Gram-positive and Gram-negative bacteria and was specific for bacterial cells E. coli O157:H7 with index of specificity equal to 9.01 in vitro assays.
在这项工作中，我们使用 GIBIM 研究小组开发的软件 DEPRAMPs 对阳离子抗菌肽 GIBIMPY4 进行了合理设计。GIBIMPY4 长 17 个氨基酸，具有两亲性，其结构为α-螺旋，净电荷为(+5)。采用 Fmoc 策略在酸性介质中进行固相肽合成。通过 MALDI-TOF 质谱法确认初级结构。采用肉汤微量稀释法测定 96 孔微孔板中的光密度来评估肽的抗菌活性。GIBIMPY4 对金黄色葡萄球菌（MRSA）和大肠杆菌 O157:H7 的半数最小抑菌浓度（MIC50）分别为 6.20 ± 0.02 μM 和 4.55 ± 0.02 μM，同时对后者具有抑菌作用。GIBIMPY4 的活性对大肠杆菌中的盐浓度敏感，但对其针对 MRSA 的活性影响不大。根据对革兰氏阳性菌和革兰氏阴性菌的结果，该肽似乎是一种广谱抗菌剂，对大肠杆菌 O157:H7 的特异性指数等于 9.01 体外试验。
