Enzymatic fragmentation of cation exchange membrane bound immunoglobulin G

Immunoglobulin G (IgG) was immobilized on a stack of microporous cation-exchange membranes and pulsed with pepsin solution. Fc fragment and its sub-fragments thus produced were removed along with the reaction flow-through, whereas F(ab')(2) which remained membrane bound could subsequently be eluted in a pure form using salt. The extent of IgG fragmentation and the apparent reaction rate constant were both significantly higher than in equivalent liquid phase reaction, presumably due to a combination of mass transport, steric, and substrate concentration effects. This approach of using a membrane surface as molecule cutting board could be attractive in niche applications such as integrated enzymatic reaction and purification processes involving macromolecular substrates.