The possibility of determining N-acetyl-beta-D-glucosaminidase isoenzymes under alkaline conditions.
OBJECTIVE
To have a reliable diagnostic test, the influence of urine pH on the determination of the total activity of N-acetyl-beta-D-glucosaminidase (NAG) and NAG isoenzyme activities was studied.


METHODS
After ultrafiltration and dialysis of the acidic and alkaline urines, the B, A, and A2 forms of NAG were separated by ion-exchange chromatography on DEAE cellulose.


RESULTS
A significant decrease in the total activity of NAG in alkaline urines (pH around 8 or higher) was found, which makes this determination unreliable. Analysis of the isoenzymic profiles obtained for weakly acidic and alkaline urines (in the pH range from 5.5. to 10.0) showed that the percent fractions of the individual isoenzyme activities in the total NAG activity and their ratios changed only at pH values above 9.5.


CONCLUSIONS
The determination of the denoted isoenzymes of urinary NAG after ultrafiltration, dialysis, and chromatographic separation on DEAE cellulose is reliable in a wide range of alkaline pH values of urine.
Mandić
Ljuba M
LM
Faculty of Chemistry, University of Belgrade, P.O. Box 158, Studentski trg 16, 11001 Belgrade, Serbia and Montenegro. ljmandic@helix.chem.bg.ac.yu
Aćimović
Jelena M
JM
Jovanović
Vesna B
VB
D000118:Acetylglucosaminidase / Q000737:chemistry* / Q000652:urine*; D002848:Chromatography, DEAE-Cellulose; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000652:urine; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014462:Ultrafiltration; D016482:Urinalysis / Q000379:methods
D007527:Isoenzymes; D000118:Acetylglucosaminidase