title: Assay of N-acetyl-beta-D-glucosaminidase in urine from neonates: comparison of two new colorimetric methods using MNP-GlcNAc and VRA-GlcNAc as substrates.
abstract: The NAG activity present in urine from newborn babies was assayed using two colorimetric procedures with either MNP-GlcNAc or VRA-GlcNAc as substrate and compared with data obtained with the well established PNP-GlcNAc procedure. Both new assays were easy to perform and reproducible. The MNP-GlcNAc method has the advantage that it is now available as a kit; however, the VRA-GlcNAc procedure is more sensitive. NAG activity, creatinine concentration and NAG-index values were determined in normal neonates and within-run imprecision calculated. Excellent correlations were found between MNP-GlcNAc-ase and VRA-GlcNAc-ase indices (r = 0.984) and between PNP-GlcNAc-ase and VRA-GlcNAc-ase indices (r = 0.952). When low molecular weight urinary components were removed by gel filtration no significant change in VRA-GlcNAc-ase activity was observed.
authors.affiliation: Institute of Biochemistry, Lajos Kossuth University, Debrecen, Hungary.
authors.forename: I
authors.initials: I
authors.lastname: Pócsi
authors.forename: L
authors.initials: L
authors.lastname: Csáthy
authors.forename: V A
authors.initials: VA
authors.lastname: Oláh
authors.forename: R G
authors.initials: RG
authors.lastname: Price
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000737:chemistry; D000118:Acetylglucosaminidase / Q000652:urine*; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000652:urine*; D008297:Male; D008722:Methods; D013844:Thiazoles / Q000737:chemistry
chemical_list: D013844:Thiazoles; C066473:5-(4-(2-acetamido-2-deoxyglucopyranosyloxy)-3-methoxyphenylmethylene)-2-thioxothiazolidin-4-one-3-ethanoate; C042999:2-methoxy-4-(2'-nitrovinyl)phenyl-2-acetamido-2-deoxy-beta-glucopyranoside; D000118:Acetylglucosaminidase; D000117:Acetylglucosamine