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.
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.
Pócsi
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Institute of Biochemistry, Lajos Kossuth University, Debrecen, Hungary.
Csáthy
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L
Oláh
V A
VA
Price
R G
RG
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
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