Bechinger Burkhard
Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany.
Biochim Biophys Acta. 2005 Jun 15;1712(1):101-8. doi: 10.1016/j.bbamem.2005.03.003. Epub 2005 Apr 1.
(31)P solid-state NMR spectroscopy has been used to investigate the macroscopic phase behavior of phospholipid bilayers in the presence of increasing amounts of magainin antibiotic peptides. Addition of >1 mol% magainin 2 to gel-phase DMPC or liquid crystalline POPC membranes respectively, results in (31)P NMR spectra that are characterized by the coexistence of isotropic signals and line shapes typical for phospholipid bilayers. The isotropic signal intensity is a function of temperature and peptide concentration. At peptide concentrations >4 mol% of the resulting phospholipid (31)P NMR spectra are characteristic of magnetically oriented POPC bilayers suggesting the formation of small disk-like micelles or perforated sheets. In contrast, addition of magainin to acidic phospholipids results in homogenous bilayer-type (31)P NMR spectra with reduced chemical shift anisotropies. The results presented are in good agreement with the interfacial insertion of magainin helices with an alignment parallel to the surface of the phospholipid bilayers. The resulting curvature strain results in detergent-like properties of the amphipathic helical peptides.
（31）P 固体核磁共振光谱已被用于研究在存在越来越多的蛙皮素抗菌肽的情况下磷脂双层的宏观相行为。分别向凝胶相 DMPC 或液晶态 POPC 膜中添加>1 mol%的蛙皮素 2，会导致（31）P 核磁共振光谱的特征是各向同性信号与磷脂双层典型的线形共存。各向同性信号强度是温度和肽浓度的函数。当肽浓度>所得磷脂的 4 mol%时，（31）P 核磁共振光谱是磁性取向的 POPC 双层的特征，表明形成了小的盘状胶束或穿孔片层。相比之下，向酸性磷脂中添加蛙皮素会导致具有降低的化学位移各向异性的均匀双层型（31）P 核磁共振光谱。所呈现的结果与蛙皮素螺旋以平行于磷脂双层表面的排列方式进行界面插入高度一致。由此产生的曲率应变导致两亲性螺旋肽具有类似去污剂的性质。
