■这项研究调查了与膜模拟系统(LUVs)的相互作用,细菌膜,CD光谱,和两个设计的曲马他辛突变体的杀菌活性,名为Trem-HK和Trem-HSK.突变体由托马他辛(Trem)的支架构建,来自南极鱼白蚁的天然22个氨基酸的AMP,旨在增加它们的正电荷。
■与Trematocine相比,设计的AMP对细菌膜的选择性得到了改善,通过它们与不同LUVs的相互作用及其膜分解活性来验证。此外,它们的α-螺旋构象不受氨基酸取代的影响。我们的发现揭示了对ESKAPE(屎肠球菌,金黄色葡萄球菌,肺炎克雷伯菌,鲍曼不动杆菌,铜绿假单胞菌,和肠杆菌科)Trem-HK和Trem-HSK的病原体。
■首先,我们表明,两种新设计的AMP对细菌膜的选择性与Trematocine相比大大提高,验证它们与不同LUVs的相互作用及其膜分解活性。我们确定它们的α-螺旋构象不受氨基酸取代的影响。我们表征了测试的细菌集合对不同类别抗生素的抗性特征。ESKAPE集合的最小抑制和杀菌浓度(MIC和MBC)值与曲马他辛相比降低了高达80%。Trematocine突变体的杀菌浓度显示出重要的膜分解作用,扫描电子显微镜很明显,所有测试的物种。我们进一步评估了突变体的细胞毒性和溶血活性。在2.5μM浓度下,两种突变体均表现出低细胞毒性和溶血,表明对细菌细胞的选择性。然而,这些影响在较高浓度时增加。
■使用Galleriamellonella模型对体内毒性的评估显示,在用两种突变体处理的幼虫中没有不良反应,即使浓度比观察到的鲍曼不动杆菌的最低MIC高20倍,表明突变体具有很高的潜在安全性。这项研究强调了通过增加Trem-HK和Trem-HSK的正电荷实现的抗菌功效的显着改善。这种改进是以降低的生物相容性为代价的。需要进一步的研究来优化这些有前途的AMP的功效和安全性之间的平衡。
UNASSIGNED: This study investigated the interaction with membrane mimetic systems (LUVs), bacterial membranes, the CD spectra, and the bactericidal activity of two designed trematocine mutants, named Trem-HK and Trem-HSK. Mutants were constructed from the scaffold of Trematocine (Trem), a natural 22-amino acid AMP from the Antarctic fish Trematomus bernacchii, aiming to increase their positive charge.
UNASSIGNED: The selectivity of the designed AMPs towards bacterial membranes was improved compared to Trematocine, verified by their interaction with different LUVs and their membranolytic activity. Additionally, their α-helical conformation was not influenced by the amino acid substitutions. Our findings revealed a significant enhancement in antibacterial efficacy against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae family) pathogens for both Trem-HK and Trem-HSK.
UNASSIGNED: Firstly, we showed that the selectivity of the two new designed AMPs towards bacterial membranes was greatly improved compared to Trematocine, verifying their interaction with different LUVs and their membranolytic activity. We determined that their α-helical conformation was not influenced by the amino acid substitutions. We characterized the tested bacterial collection for resistance traits to different classes of antibiotics. The minimum inhibitory and bactericidal concentration (MIC and MBC) values of the ESKAPE collection were reduced by up to 80% compared to Trematocine. The bactericidal concentrations of Trematocine mutants showed important membranolytic action, evident by scanning electron microscopy, on all tested species. We further evaluated the cytotoxicity and hemolytic activity of the mutants. At 2.5 μM concentration, both mutants demonstrated low cytotoxicity and hemolysis, indicating selectivity towards bacterial cells. However, these effects increased at higher concentrations.
UNASSIGNED: Assessment of in vivo toxicity using the Galleria mellonella model revealed no adverse effects in larvae treated with both mutants, even at concentrations up to 20 times higher than the lowest MIC observed for Acinetobacter baumannii, suggesting a high potential safety profile for the mutants. This study highlights the significant improvement in antibacterial efficacy achieved by increasing the positive charge of Trem-HK and Trem-HSK. This improvement was reached at the cost of reduced biocompatibility. Further research is necessary to optimize the balance between efficacy and safety for these promising AMPs.