Multiple forms of N-acetyl-beta-D-glucosaminidase of human urine: isolation, properties and the development of a practical approach of differentiation.

The two major tissue forms of N-acetyl-beta-D-glucosaminidase, A and B, and a minor form M were isolated from human urine by chromatography on DEAE-Trisacryl M and Con A-Sepharose. Forms A and B have a Km-value of about 0.75 mM for 4-nitrophenyl-beta-2-acetamido-2-deoxy-D-glucopyranoside, form M a corresponding value of 1.57 mM. The pH optimum was for all forms between pH 4.0 and 4.8. Forms A and M were heat labile, while form B was relatively heat stable. Using different binding properties of forms A and B on Trisacryl, a batch method was developed to differentiate both forms in human urine. This method can be easily performed and gives reproducible results. The intra-run and between-run precision for the separation of the two forms were below 10%.