Polyclonal-antibody-mediated insolubilization and stabilization of papain

Antisera raised in rabbits against native iodo-acetamide- and iodoacetic ac id-modified papain contained precipitating and non-inhibitory antibodies. P apain could be insolubilized as enzyme-antibody adducts with the gamma-glob ulin fraction; derived from the antiserum. Two insolubilized papain prepara tions, designated A and B, with low and high antibody/enzyme ratios, respec tively, exhibited high enzyme activity and markedly enhanced thermal and de naturant stabilities. However, papain antibody adduct B was superior in act ivity and stability over preparation A. The usefulness of immobilized papai n in biopharmaceutical and other industries is also discussed.