Immobilization of yeast pyridoxaminephosphate oxidase to halogenoacetyl polysaccharides

Pyridoxaminephosphate oxidase (EC 1.4.3.5, deaminating) that was partially purified about 40-fold from dry baker's yeast was immobilized to iodo- and bromoacetyl polysaccharides. The most effective carrier was an iodoacetyl cellulose, to which almost complete activity of pyridoxine 5'-phosphate oxidase was immobilized in 0.02M potassium phosphate buffer (pH 8.5) containing 2M ammonium sulfate at 4 degrees C. The immobilized enzyme was more stable than the purified, soluble enzyme against heat and pH change. It was confirmed that N-(5'-phosphopyridoxyl)-L-serine was degradedly oxidized to pyridoxal 5'-phosphate and L-serine by the immobilized enzyme as comparable rate as pyridoxine 5'-phosphate, whereas N-(5'-phosphopyridoxyl)-D-serine did not serve as substrate, as in the purified, soluble enzyme.