The cell penetrating peptides pVEC and W2-pVEC induce transformation of gel phase domains in phospholipid bilayers without affecting their integrity
The cell penetrating peptides pVEC and W2-pVEC induce transformation of gel phase domains in phospholipid bilayers without affecting their integrity
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DOI：
10.1021/bi050923c
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发表时间：
2006-03-21
期刊：
影响因子：
2.9
通讯作者：
Merkle, HP
中科院分区：
文献类型：
--
作者：
Herbig, ME;Assi, F;Merkle, HP
细胞穿透肽（CPP）pVEC通过受体非依赖性机制有效地转位不同哺乳动物细胞系的质膜而不表现出细胞毒性。这种能力使得CPP在细胞生物学、生物技术和药物递送方面具有广泛的兴趣。为了深入了解CPPs与生物膜的相互作用，我们用原子力显微镜（AFM）研究了pVEC和W2-pVEC（前者的Ile -> Trp修饰）与相分离的支撑磷脂双层（SPB）的相互作用。W2-pVEC诱导二棕榈酰磷脂酰胆碱（DPPC）结构域从凝胶相状态通过具有分支结构的中间状态转化为基本上平坦的双层。pVEC的转化遵循类似的途径，但较慢。采用荧光偏振，我们揭示了能力的调查肽，以增加流动性的DPPC域的潜在机制的转变。由于其更紧密的包装，鞘磷脂（SM）结构域没有被转化。通过组合，AIM观察、动态光散射研究和脂质体渗漏实验表明，肽不会损害双层完整性。CPPs对SPB凝胶相结构域的转化是CPPs摄取机制研究的一个新的方面。
The cell penetrating peptide (CPP) pVEC has been shown to translocate efficiently the plasma membrane of different mammalian cell lines by a receptor-independent mechanism without exhibiting cellular toxicity. This ability renders CPPs of broad interest in cell biology, biotechnology, and drug delivery. To gain insight into the interaction of CPPs with biomembranes, we studied the interaction of pVEC and W2-pVEC, an Ile --> Trp modification of the former, with phase-separated supported phospholipid bilayers (SPB) by atomic force microscopy (AFM). W2-pVEC induced a transformation of dipalmitoyl phosphatidylcholine (DPPC) domains from a gel phase state via an intermediate state with branched structures into essentially flat bilayers. With pVEC the transformation followed a similar pathway but was slower. Employing fluorescence polarization, we revealed the capability of the investigated peptides to increase the fluidity of DPPC domains as the underlying mechanism of transformation. Due to their tighter packing, sphingomyelin (SM) domains were not transformed. By combination, AIM observations, dynamic light scattering studies, and liposome leakage experiments indicated that bilayer integrity was not compromised by the peptides. Transformation of gel phase domains in SPB by CPPs represents a novel aspect in the discussion on uptake mechanisms of CPPs.