The mechanism of action of the anti-Listeria peptide enterocin CRL35 was studied with biophysical tools by using lipid mixtures that mimicked Gram-positive plasma membranes. Langmuir monolayers and infrared spectroscopy indicated that the peptide readily interacted with phospholipid assembled in monolayers and bilayers to produce a dual effect, depending on the acyl chains. Indeed, short chain mixtures were disordered by enterocin CRL35, but the gel-phases of membranes composed by longer acyl chains were clearly stabilized by the bacteriocin. Structural and functional studies indicated that non-bilayer states were formed when liposomes were co-incubated with enterocin CRL35, whereas significant permeabilization could be detected when bilayer and non-bilayer states co-existed. Results can be explained by a two-step model in which the N-terminal of the peptide firstly docks enterocin CRL35 on the lipid surface by means of electrostatic interactions; then, C-terminal triggers membrane perturbation by insertion of hydrophobic α-helix.

中文翻译：

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细菌素肠球菌CRL35是一种模块化肽，可在细菌模型膜中诱导非双层状态。

通过使用模拟革兰氏阳性质膜的脂质混合物，使用生物物理工具研究了抗李斯特菌肽肠球菌素CRL35的作用机理。Langmuir单层和红外光谱表明，根据酰基链的不同，该肽易于与组装成单层和双层的磷脂相互作用，产生双重作用。确实，短链混合物被肠球菌CRL35所扰乱，但是由较长的酰基链组成的膜的凝胶相却被细菌素稳定了。结构和功能研究表明，脂质体与肠球菌素CRL35共同孵育时会形成非双层状态，而双层和非双层状态共存时则可以检测到明显的通透性。结果可以通过两步模型来解释，其中肽的N端首先通过静电相互作用将肠溶菌素CRL35对接在脂质表面上；然后，C末端通过插入疏水性α-螺旋触发膜扰动。