Purification and partial characterization of N-acetyl-beta-D-glucosaminidase from Tritrichomonas foetus

Cells of Tritrichomonas foetus were suspended in buffer (0.1 M phosphate, 0.15 M NaCl, pH 7), sonicated for 2 min on ice, and centrifuged at low speed (500 g/40 min) at 4 degrees C. The resulting supernatant was centrifuged at 100,000 g for 30 min at 4 degrees C. The N-acetyl-beta-D-glucosaminidase activity as assayed by fluorimetric assay using 4-methylumbelliferil beta-D-N-acetylglucosamine (4MU-GlcNAc) was found predominantly (> 95%) in the supernatant. Isolation of the enzyme was achieved by a combination of gel filtration with ion-exchange chromatography. Non-denaturing gel electrophoresis indicated that N-acetyl-beta-D-glucosaminidase activity was present in two bands. When the two fluorescent bands were excised from the non-denaturing gel and rerun on denaturing 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis they exhibited two proteins with molecular masses of 40 and 45 kDa. The pH optimum is approximately 7.5 and the temperature optimum is approximately 37 degrees C.