Formation of supramolecular structures from globular proteins: case of alpha-lactalbumin in association with lysozyme
Résumé
Self-assembling food proteins offer great potential as scaffolds for building bio-inspired materials and controlled development of supramolecular structures with new functionalities. We have conducted an exhaustive study on the interaction and self-assembly occurring between a-lactalbumin and lysozyme, two homologous oppositely charged globular proteins. Under controlled physico-chemical conditions, we showed that the self-assembly process between these two proteins can be oriented towards the formation of original spherical particles of about 2-3 μm. The mechanism behind such protein self-assembly and the properties of formed microspheres were further investigated. In this communication, we will address first the initial step of the interaction leading to the formation of heterodimers as assessed by fluorescence techniques [1]. The propensity of formed heterodimers to further self assemble into supramolecular structures is discussed on the light of subtle conformational change occurring on a-lactalbumin and consequently on formed heterodimers according to the temperature and the presence of calcium ions [2,]. Secondly, we will report on the main properties of formed microspheres as revealed by microscopic techniques in particular how both proteins are arranged into formed supra-molecular structures. Finally, based on kinetic studies, we will discuss a possible mechanism for the formation of α-Lactalbumin/Lysozyme microspheres [3].