LAUSR

Abstract Self-organization of proteins and non-ionic surfactants at the aqueous-air and aqueous-organic liquid interfaces is controlled by hydrophobic interactions. Unfortunately, little is quantitatively known about the effects of high- and low-molecular weight non-ionic surfactants on protein adsorption and aggregation at aqueous-air and aqueous-organic liquid interfaces. A tritium probe technique was applied to the systems lysozyme – Pluronic P123 and lysozyme – Brij-35. For complex analysis, UV and fluorescent spectrometry were also used for solutions with the chosen protein and surfactants concentrations. Non-ionic surfactants form a flexible complex with lysozyme at the aqueous-air interface. We observed that both Pluronic P123 and Brij-35 result in displacement of 40–75 % of protein, even in a surfactant concentration range less than the CMC and rotation of residual protein (or protein in complex with surfactant) in the mixed adsorption layer compared to the adsorption layer formed by free lysozyme. In the mixed adsorption layer, lysozyme globules are separated, and protein becomes more available for tritium atoms compared to free lysozyme.