Li Wenyi, Sani Marc-Antoine, Jamasbi Elaheh, Otvos Laszlo, Hossain Mohammed Akhter, Wade John D, Separovic Frances
School of Chemistry, Bio21 Institute, University of Melbourne, VIC 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, VIC 3010, Australia.
School of Chemistry, Bio21 Institute, University of Melbourne, VIC 3010, Australia.
Biochim Biophys Acta. 2016 Jun;1858(6):1236-43. doi: 10.1016/j.bbamem.2016.02.035. Epub 2016 Feb 27.
The increasing prevalence of antibiotic-resistant pathogens requires the development of new antibiotics. Proline-rich antimicrobial peptides (PrAMPs), including native apidaecins, Bac7, and oncocins or designed A3APO, show multi-modal actions against pathogens together with immunostimulatory activities. The interactions of the designed PrAMP, Chex1-Arg20, and its dimeric and tetrameric oligomers with different model membranes were investigated by circular dichroism spectroscopy, dynamic light scattering, zeta potential, differential scanning calorimetry, and dye leakage. Chex1-Arg20 oligomers showed stronger affinity and preferential binding to negatively charged phospholipid bilayers and led to lipid aggregation and neutralization. Fluorescence microscopy of negatively charged giant unilamellar vesicles with AlexFluor-647-labeled Chex1-Arg20 dimers and tetramers displayed aggregation at a peptide/lipid low ratio of 1:200 and at higher peptide concentrations (1:100/1:50) for Chex1-Arg20 monomer. Such interactions, aggregation, and neutralization of PrAMP oligomers additionally showed the importance of interactions of PrAMPs with negatively charged membranes.
抗生素耐药性病原体的日益流行促使人们开发新的抗生素。富含脯氨酸的抗菌肽（PrAMPs），包括天然的蜜蜂抗菌肽、Bac7和癌胚素，或设计的A3APO，对病原体具有多模式作用，并具有免疫刺激活性。通过圆二色光谱、动态光散射、zeta电位、差示扫描量热法和染料泄漏研究了设计的PrAMP、Chex1-Arg20及其二聚体和四聚体低聚物与不同模型膜的相互作用。Chex1-Arg20低聚物对带负电荷的磷脂双层表现出更强的亲和力和优先结合，并导致脂质聚集和中和。用AlexFluor-647标记的Chex1-Arg20二聚体和四聚体对带负电荷的巨型单层囊泡进行荧光显微镜观察，结果显示在肽/脂质低比例为1:200时以及Chex1-Arg20单体处于较高肽浓度（1:100/1:50）时会发生聚集。PrAMP低聚物的这种相互作用、聚集和中和进一步表明了PrAMPs与带负电荷膜相互作用的重要性。
