A large‐scale purification of beta‐glucuronidase from human liver by immunoaffinity chromatography

We intend to purify beta-glucuronidase from human liver in a large quantity in order to facilitate the study of its biochemical structure and pathophysiologic roles in cholelithiasis and carcinogenesis. The initial purification procedure involved: (1) liver homogenization, (2) 25-45% saturated ammonium sulfate fractionation, (3) heat denaturation of protein at 56 degrees C, (4) gel filtration with Bio-Gel P-300 gel, (5) anion exchange chromatography with DEAE agarose, (6) cation exchange chromatography with CM agarose, and (7) hydroxyapatite chromatography (overall yield, 1%; overall purification, 169X). The final product was used to immunize rabbits and BALB/c mice for production of polyclonal and monoclonal antibodies, respectively. The antibodies, mainly IgG, were purified by using gamma-Protein A agarose column chromatography. The purified IgG, after periodate oxidation, was coupled to hydrazide gel by formation of a stable covalent hydrazone bond linkage. The new purification procedure involved the initial first three steps, followed by (4) polyclonal IgG immunoaffinity chromatography and (5) monoclonal IgG immunoaffinity chromatography (overall yield, 6.1%; overall purification, 3720X). Polyacrylamide gel electrophoresis indicated minor contaminants in the final product which could be further purified by electroelution. It is concluded that beta-glucuronidase constitutes 0.016 mg per gram of wet liver tissue and can be obtained on a large scale in a highly purified form within a 2-day cycle.