Laboratoire d'Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne, Station 6, CH-1015 Lausanne, Switzerland.
Langmuir. 2011 Nov 15;27(22):13918-24. doi: 10.1021/la202970g. Epub 2011 Oct 19.
Melittin, a membrane-active peptide with antimicrobial activity, was investigated at the interface formed between two immiscible electrolyte solutions (ITIES) supported on a metallic electrode. Ion-transfer voltammetry showed well-defined semi-reversible transfer peaks along with adsorptive peaks. The reversible adsorption of melittin at the liquid-liquid interface is qualitatively discussed from voltammetric data and experimentally confirmed by real-time image analysis of video snapshots. It is also demonstrated that polarization of the water/1,2-DCE interface results in drastic drop shape variations caused by large variations of the interfacial tension. The experimental data also confirmed that maximum adsorption occurs near the ion transfer potential. Finally, the interaction of melittin with a monolayer of L-α-dipalmitoyl phosphatidylcholine (DPPC) was also investigated showing that melittin destabilizes the lipidic monolayer facilitating its desorption. The non-covalent complex formation between melittin and DPPC was confirmed by mass spectrometry.
蜂毒素是一种具有抗菌活性的膜活性肽，本研究采用离子液体/水界面作为研究模型，通过在金属电极上支持两种不混溶的电解质溶液（ITIES）来研究其在界面处的行为。离子转移伏安法显示出具有良好定义的准可逆转移峰和吸附峰。从伏安数据定性讨论了蜂毒素在液/液界面上的可逆吸附，并通过实时视频快照的图像分析实验证实。实验结果还表明，水/1,2-二氯乙烷界面的极化会导致界面张力的剧烈变化，从而导致明显的波状变化。实验数据还证实，最大吸附发生在离子转移电位附近。最后，还研究了蜂毒素与单层 L-α-二月桂酰基磷脂酰胆碱（DPPC）的相互作用，结果表明蜂毒素会破坏脂质单层，促进其解吸。通过质谱证实了蜂毒素与 DPPC 之间形成非共价复合物。
