Karlsruhe Institute of Technology (KIT), Institute of Biological Interfaces (IBG-2), Karlsruhe, Germany.
Biophys J. 2013 Mar 19;104(6):L9-11. doi: 10.1016/j.bpj.2013.01.047.
PGLa and magainin 2 (MAG2) are amphiphilic antimicrobial peptides from frog skin with known synergistic activity. The orientation of the two helices in membranes was studied using solid-state (15)N-NMR, for each peptide alone and for a 1:1 mixture of the peptides, in a range of different lipid systems. Two types of orientational behavior emerged. 1), In lipids with negative spontaneous curvature, both peptides remain flat on the membrane surface, when assessed both alone and in a 1:1 mixture. 2), In lipids with positive spontaneous curvature, PGLa alone assumes a tilted orientation but inserts into the bilayer in a transmembrane alignment in the presence of MAG2, whereas MAG2 stays on the surface or gets only slightly tilted, when observed both alone and in the presence of PGLa. The behavior of PGLa alone is identical to that of another antimicrobial peptide, MSI-103, in the same lipid systems, indicating that the curvature-dependent helix orientation is a general feature of membrane-bound peptides and also influences their synergistic intermolecular interactions.
PGLa 和 magainin 2（MAG2）是来自青蛙皮肤的两亲性抗菌肽，具有已知的协同活性。使用固态（15）N-NMR 研究了两种肽在一系列不同脂质系统中单独使用和 1:1 混合物时在膜中的取向。出现了两种类型的取向行为。1），在具有负自发曲率的脂质中，当单独评估和在 1:1 混合物中评估时，两种肽都保持在膜表面上是平坦的。2），在具有正自发曲率的脂质中，PGLa 单独采取倾斜取向，但在 MAG2 存在下插入双层膜中呈跨膜排列，而 MAG2 留在表面上或仅略微倾斜，无论是单独观察还是在 PGLa 存在下观察到。PGLa 单独的行为与同一脂质系统中的另一种抗菌肽 MSI-103 相同，表明曲率依赖性螺旋取向是膜结合肽的一般特征，也影响它们的协同分子间相互作用。
