Enzymic membrane pumps for specific active transport of small hydrophilic molecules: improvement of the process

Abstract The use of a phosphatase and a kinase covalently bound on both parts of a porous artificial membrane has led us to demonstrate that two opposite reactions occurring at a pore entrance/exit and in unstirred layers can behave as a specific membrane pump. Such an enzymic pump was found to be able to concentrate specifically a given small phosphorylated molecule against its chemical gradient. The corresponding theoretical analysis of such a phenomenon predicted that both the kinetics of this transport and the concentration ratio expected in the receiving chamber of a diffusion cell might be improved. The comparison of four different membrane structures has led us to corroborate experimentally the predictions of this new theory. With the most appropriate membrane used in this study, a concentration ratio of nine times was obtained in 500 min.