title: The possibility of determining N-acetyl-beta-D-glucosaminidase isoenzymes under alkaline conditions.
abstract: 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.
authors.affiliation: Faculty of Chemistry, University of Belgrade, P.O. Box 158, Studentski trg 16, 11001 Belgrade, Serbia and Montenegro. ljmandic@helix.chem.bg.ac.yu
authors.forename: Ljuba M
authors.initials: LM
authors.lastname: Mandić
authors.forename: Jelena M
authors.initials: JM
authors.lastname: Aćimović
authors.forename: Vesna B
authors.initials: VB
authors.lastname: Jovanović
mesh_terms: 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
chemical_list: D007527:Isoenzymes; D000118:Acetylglucosaminidase