The investigation of the effects of cholesterol and cholesterol analogs on lipid membranes by using spectroscopic and calorimetric techniques

Sterols are a common component of biological membranes and affect both physical and functional properties of membranes. The interaction of sterols, especially cholesterol and cholesterol analogs, with phospholipids and sphingolipids is also important for the structural and dynamic properties of biological membranes. Since biological membranes have a quite complex structure, studying with model membranes, that we can change the number and concentration of their components, is important in explaining the events in biological membranes. In this study, physical interactions, i.e. membrane phase transitions, membrane organization and membrane dynamics, of cholesterol and cholesterol analogs with model membranes composed of phospholipids and sphingolipids, and thermal changes occured by the incorporation of these sterols into model membranes have been investigated using FTIR and DSC techniques depending on temperature and concentration. This study has gained a great importance as supporting and guiding experimental studies in the sense of the molecular basis of the interaction of phospholipids and sphingolipid membranes used as models for biological membranes with each other and different molecules.The results obtained from this study have helped us to better understand the mechanism of action of sterols, such as cholesterol and cholesterol analogs used in the treatment of various diseases and diseases, in the real system.