Role of membrane proteins β- and α-structures in plasmalemm structure change

Changes in the structure of plasma membranes affect the functions of membranes and cells. Some of these changes can lead to the development of pathologies of the body, which makes it actually to study the effect of changes in the structure of membranes on their functions. It has now been established that when stress hormones and androgens interact with plasma membranes, their structure changes. At the same time, interactions between proteins and lipids change in plasmalemmas, and a fixed quasi-periodic network of protein-lipid domains associated with the cytoskeleton is formed. The initiators of the formation of protein-lipid domains are membrane proteins, which have changed their secondary structure during the interaction of the membrane with hormones. However, it is still unclear exactly what changes in the secondary structure of membrane proteins contribute to the formation of protein-lipid domains around them. The aim of this work was to establish these secondary structures of membrane proteins. To achieve this goal, changes in the structure of membranes during their interaction with dehydroepiandrosterone, cortisol, androsterone, testosterone, and adrenaline were studied. In this work, a fluorescent method for measuring the relative microviscosity of membranes using a pyrene probe was used to study changes in the membrane structure. The change in the secondary structure of membrane proteins during structural transitions in membranes was studied by measuring the IR absorption spectra of membranes. It has been established that the initiators of the appearance of protein-lipid domains in plasma membranes are membrane proteins, in which, after interaction with hormones, the proportion of β-structures increases. At the same time, the appearance of new α-helices in membrane proteins does not enhance the attraction between membrane proteins and protein-lipid domains are not formed. On the contrary, the appearance of a large number of α-helices in membrane proteins can lead to a decrease in the microviscosity of the lipid bilayer.