If biological membranes were not fluid, it is hard to imagine how cells could live, grow, and reproduce. The content of membranes defines their physical and biological properties.
This statement is so widely accepted by biologists that little attention is generally given to the theoretical importance of cell membranes in describing the cell. It is obvious, however, that some well-known and widely used drug should be studied first to show that the difference in permeability between normal and cancer cell membranes exists.
They can be classified according to their relationship with the bilayer: Integral polytopic proteins are transmembrane proteins that span across the membrane more than once. Peripheral membrane proteins[ edit ] Schematic representation of the different types of interaction between monotopic membrane proteins and the cell membrane : 1.
Serine and ethanolamine can replace the choline in this position, and these lipids are called phosphatidylserine PS and phosphatidylethanolamine PErespectively.
One of the major concerns comes from the difficulty of determining equilibrium state of the ligand in the membrane related to extremely slow transitions in bilayer structure, which occur on the time scale well beyond the capabilities of routine all-atom MD simulations