[Permeability of artificial lipid membranes to some enzymes]

The permeability of artificial lipid membranes for six enzymes, e.g. RNAse, trypsin, amylase, aldolase, invertase and alkaline phosphatase, was studied. The permeability coefficient values for these enzymes were calculated. It was shown that the penetration process consists of several steps: adsorption of enzyme on the membrane surface, diffusion of enzyme molecules through the lipid layer and enzyme desorption into the surrounding solution. The results obtained suggest that the diffusion of the enzyme molecules through the lipid layer is the limiting step of the penetration process.