An epoxy-activated silica column (50 cm x 0.45 cm I.D.) was derivatized with 8-[6-aminohexyl)amino]-2'-phosphoadenosine-5'-diphosphoribose; the bound ligand concentration was 11.4 mumol/g of dry silica, and the useful loading capacity was 2.3 mg of glutathione reductase. The new high-performance liquid chromatographic column specifically retained NADP(+)-dependent enzymes, which were quantitatively eluted specifically by NADP+ or, with better resolution, by potassium chloride. The new high-performance liquid chromatographic support was applied to the purification of glutathione reductase and glucose-6-phosphate dehydrogenase from cell-free extracts of baker's yeast, fish liver and rabbit hemolysates, with high recoveries and excellent purification factors.