Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal.
Biopolymers. 2010;94(3):314-22. doi: 10.1002/bip.21367.
The use of peptide carriers, termed "cell-penetrating peptides (CPPs)" has attracted much attention due to their potential for cellular delivery of hydrophilic molecules with pharmacological interest, overcoming the membrane barrier. These peptides are able to deliver attached cargos in a nontoxic manner, with the uptake mechanisms being either endosomally or physically driven. Pep-1 is a CPP of particular interest, not only due to outstanding delivery rates but also because its mechanism of membrane translocation is exclusively physically driven which appears to be dependent on a very high affinity for the phospholipid bilayer in the cell membrane. In this study, pep-1-lipid interactions were further explored by characterization of the pep-1-lipid association/dissociation by surface plasmon resonance. Although a high affinity of pep-1 for lipid bilayers was observed in all conditions tested, negatively charged phospholipids resulted in a larger peptide/lipid ratio. We also show that pep-1-membrane interaction is a fast process described by a multistep model initiated by peptide adsorption, primarily governed by electrostatic attractions, and followed by peptide insertion in the hydrophobic membrane core. In the context of a cell-based process, the translocation of pep-1 is a physical mechanism promoted by peptide primary amphipathicity and asymmetric properties of the membrane. This explains the high efficiency rates of pep-1 when compared with other CPPs.
由于肽载体（称为“细胞穿透肽 (CPP) ”）具有将具有药理兴趣的亲水分子递送至细胞内的潜力，因此克服了细胞膜的障碍，引起了广泛关注。这些肽能够以非毒性的方式递送电荷货物，摄取机制可以是内吞作用或物理驱动。Pep-1 是一种特别有趣的 CPP，不仅因为其出色的递送率，而且因为其膜转位的机制完全是物理驱动的，这似乎依赖于与细胞膜中磷脂双层的极高亲和力。在这项研究中，通过表面等离子体共振对 pep-1-脂质的缔合/解离进行表征，进一步探索了 pep-1-脂质的相互作用。尽管在所有测试条件下都观察到 pep-1 与脂质双层具有高亲和力，但带负电荷的磷脂会导致更大的肽/脂质比例。我们还表明，pep-1-膜相互作用是一个快速过程，由肽吸附引发，主要由静电吸引力控制，然后由肽插入疏水性膜核心组成。在基于细胞的过程中，pep-1 的转位是由肽的初级两亲性和膜的不对称性质促进的物理机制。这解释了 pep-1 与其他 CPP 相比效率更高的原因。
