Аннотация:Many enzymes in vivo function in a tight contact with biological membranes. Their catalytic activity depends on the nature of membrane microenvironment. One of the factors that can play a key role is the lipid structure and phase transitions occuring at different conditions. The ternary surfactant-water-organic solvent systems were proposed as a medium for modeling the membrane environment of enzymes. The surfactant molecules in these systems (including membrane lipids) can form aggregates of different structure. Enzymes of various origins were solubilized in such systems and were found to function in different mesophases: reverse micellar, lamellar, reverse hexagonal, cubic, etc. Phase transitions in the ternary system resulting from the change of the concentration ratio can cause dramatic changes in the enzyme catalytic activity. Pressure was found to be one of the powerful factors in the enzyme structure and activity regulation. The paper discusses perspectives of using pressure as a new factor in enzyme regulation because of its participation in structural rearrangements in the ternary surfactant-based system.