I teach in the Master's program in Biochemistry and serve as a teaching assistant for the Structure and Dynamics of Biological Membranes course (KB7022).

Every living organism – from tiny bacteria to complex humans – is made up of cells. Every cell is wrapped in a protective, yet flexible and dynamic barrier called the cell membrane, or more specifically, the plasma membrane. Beyond its function as a barrier, the plasma membrane also controls the flow of nutrients and information between the cell and its surroundings, and hosts different kinds of proteins, some embedded within it and others attached to its surface. The main building block of this membrane are lipids – a class of molecules that is generally characterized by their inability to mix with water (hydrophobicity). Phospholipids are particularly important for the structure of the cell membrane. Each phospholipid consists of a hydrophilic headgroup that interacts well with water and two hydrophobic chains. Since both the inside and outside of the cell are water-based environments and the hydrophobic chains minimize their exposure to water, phospholipids naturally arrange themselves into a double layer, known as a lipid bilayer. In this structure, the hydrophilic headgroups face outward towards the surrounding fluid while the hydrophobic chains are packed together in the middle. The phenomenon that drives this self-organization of lipids is known as the hydrophobic effect.
Intriguingly, the lipid bilayer is asymmetric: The inner and outer layers differ in both the types and numbers of lipids they contain. This number asymmetry is surprising because the cell membrane forms a closed surface and both layers have the same area, so one might expect them to contain at least similar numbers of lipids. Cells invest considerable energy to maintain these lipid imbalances, which emphasizes the essential role of plasma membrane lipid organization in biological processes. However, despite decades of research, scientists are still trying to understand exactly how this asymmetry affects the properties of the membrane, for instance the permeability, fluidity or protein-lipid interactions, and cell function.
In our lab, we tackle this puzzling question by combining computer simulations with hands-on experiments, creating synthetic membrane systems that mimic real cell membranes. By studying these models, we can explore how membrane asymmetry influences membrane properties, ultimately gaining a better understanding of how cells work. Beyond fundamental insights into biological systems, our research could reveal means to manipulate asymmetry, unlocking the hidden therapeutic potential in lipid organization and enabling new ways of tuning bilayer properties for improved liposomal formulations for clinical applications.

Want to know more? Check out our lab’s website at: https://www.doktorovaresearch.com