WETMORE, S. J., and VERPBORTE, J. A. The partial purification of two B-N-acetyl-D-hexosaminidases from porcine kidney. Can. J. Biochem. 50,563-573 (1972).Two distinct fractions showing both B-N-acetyl-D-glucosaminidase (EC 3.2.1.30) and 8-N-acetyl-sgalactowminidase activity were isolated and purified from pig kidney. These preparations, which were designated A and B, were not stable during gel chromatography or prolonged dialysis. Final purifications of 600-fold for enzyme A and 440-fold for enzyme B were obtained.Gel electrophoresis and ultracentrifugation studies indicated heterogeneity in both preparations. The amino acid compositions of both preparations were very similar. Ultracentrifugation studies suggested the formation of subunits in the presence of 5 M guanidine-HCl and 1 mM dithiothreitol.A study of the enzymatic properties also showed great similarities between the two enzyme forms. Both enzymes had identical Michaelis-Menten constants of 1.88 mM forp-nitrophenyl-8-N-acetyl-D-glucosaminide and 0.38 mM for p-nitrophenyl-B-N-acetyl-D-galactosaminide. Although bovine serum albumin enhanced the activity of the enzymes it did not change the K, values. The pH-rate profiles of both enzymes with the substrate p-nitrophenyl-B-N-acetyl-D-glucodnide showed two peaks. When p-nitrophenyl-p-N-acetyl-Dgalactosaminide was used as substrate, only one peak was observed in the pH-rate profiles. However, in this case a distinct shoulder could be detected in these peaks. Heating at SO0 destroyed the activities of both forms of the enzyme rapidly, but addition of bovine senun albumin protected against heat inactivation. WETMORE, S. J., et VERPOBRTE, J. A. The partial purification of two B-N-acetyl-D-hexosaminidases from porcine kidney. Can. J. Biochem. 58, 563-573 (1972). Deux fractions distinctes poss&bnt chacune une B-N-acktyl-D-glucosaminidase (EC 3.2.1.30) et une B-N-acktyl-D-galactosaminidase sont isolbes et purifiks a partir du rein de porc. Ces dew preparations, nommtes A et B, sont instables durant la chromatographie sur gel ou durant une dialyse prolongee. La purification finale de l'enzyme A est de 600 fois et celle de l'enzyme B, de 440 fois. L'tlectrophorese sur gel et l'ultracentrifugation dtmontrent l'httkroginkitt des deux preparations. Les compositions en acides amints des deux preparations se ressemblent beaucoup. Les rbultats de l'ultracentrifugation laissent croire A la formation de sous-unites en presence de guanidine-HC1 5 M et de dithiothrkitol 1 mM. L'etude des proprietes enzymatiques rkvele aussi une grande similitude entre les deux enzymes. Tous dew ont la meme constante de Michaelis-Menten pour le p-nitrophknyl-B-N-acktyl-D-glucosaminide (1.88 mM) et pour le p-nitrophtnyl-B-N-acttyl-s-galactoaminde (0.38 mM). Bien que l'albumine krique du boeuf augmente l'activitk de ces enzymes, elle ne change par leurs valeurs de K,. Avec lep-nitrophknyl-8-N-acktyl-Dgucosaminide, les courbes en fonction du pH montrent deux sommets. Avec le p-nitrophknyl-B-N-acCtyl-Dgalactosaminide, ces courbes n'offrent plus qu'...