THE ACCELERATION OF L-LYSINE TRANSPORT THROUGH POLY(ALPHA-AMINO ACID) MEMBRANES IN ACID WATER

pH-induced transport control of L-lysine through membranes of poly( alpha -amino acid) with amino groups in the side chains, i. e. , methyl L-glutamate (MG)-N**5-(2 aminoethyl)-glutamine (AEG) copolymer membranes, was investigated. MG/AEG copolymer crosslinked membranes were obtained by the aminolysis reaction of poly( gamma -methyl L-glutamate) (PMLG) solid membrane with ethylenediamine. AEG content of the polymers was regulated by the reaction time. The degree of hydration and area of the MG/AEG copolymer membrane increased with decreasing pH of aqueous solution, reflecting ionization changes of the AEG moiety. This increase was particularly remarkable for the copolymer membrane containing more than 42 mol% of AEG residues owing to their main chain conformational transition.