Electrocapillary Curves for the Polarisable Liquid-Liquid Interface in Presence of the Peptide Melittin

The adsorption of the anti-microbial peptide melittin at the polarisable water/1,2-DCE (W-DCE) interface is expected to manifest itself by changes in the interfacial tension. These interfacial tension changes during the peptide adsorption at the interface were measured by a custom-built quasi-elastic light scattering (QELS) setup. Electrocapillary curves obtained for melittin at physiological pH evidences the strong affinity of this peptide for the W-DCE interface. In other words, it is evident that at negative potentials the peptide are readily adsorbed and that at more positive potentials desorption of adsorbed peptide from the interface proceeds leading to an increase of interfacial tension.