Figure 1: Compression isotherms of surface pressure, versus , (curves 1 and 2) and electric surface potential, versus (curves 1′ and 2′) of: (a) DPPC and (b) DPPG monolayers spread on subphase of water (curves 1 and 1′) and lactophoricin (N-23-T) solution, 1 μM (curves 2 and 2′); “ ” denotes area per the phospholipid molecule. The inserts show the surface compression modulus ( ) calculated according to (1) as a function of of the pure lipid monolayer (solid lines) and that spread on lactophoricin solution (dotted lines).