Analysis of urinary N-acetyl-beta-D-glucosaminidase using 2,4-dinitrophenyl-1-thio N-acetyl-beta-D-glucosaminide as the substrate.
2,4-Dinitrophenyl-1-thio N-acetyl-beta-D-glucosaminide was examined as a new substrate for analyzing the level of N-acetyl-beta-D-glucosaminidase in the urine of patients suffering from renal diseases. The analysis is based on the fact that the substrate, when hydrolyzed in the presence of N-acetyl-beta-D-glucosaminidase, liberates 2,4-dinitrothiophenol as the chromogen. The optimum pH for the enzyme reaction is 4.6, which is covered by the optimal range for the UV absorbance of the chromogen. The first-order rate of increase of the absorbance at this pH was linear to the enzyme concentration up to 600 U/L, with a high sensitivity. Analytical reagents with glucosaminides of 2,4-dinitrophenol and 2-chloro-4-nitrophenol are less stable than the reagent with glucosaminide of 2,4-dinitrothiophenol. The optimum pH for the absorbance of p-nitrophenol and 2-chloro-4-nitrophenol does not match that for the enzyme reaction.
Yamada
Magohei
M
International Reagents Company, Ltd., Kobe, Japan.
Fujita
Toshio
T
D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000378:metabolism*; D000118:Acetylglucosaminidase / Q000652:urine*; D003404:Creatinine / Q000652:urine; D006801:Humans; D007674:Kidney Diseases / Q000652:urine; D013379:Substrate Specificity; D013863:Thioglucosides / Q000138:chemical synthesis / Q000378:metabolism*
C482651:2,4-dinitrophenyl-1-thio N-acetylglucosaminide; D013863:Thioglucosides; D003404:Creatinine; D000118:Acetylglucosaminidase; D000117:Acetylglucosamine