Open AccessAnalysis of urinary N ‐acetyl‐β‐ D ‐glucosaminidase using 2,4‐dinitrophenyl‐1‐thio N ‐acetyl‐β‐ D ‐glucosaminide as the substrate
Author(s) -
Yamada Magohei,
Fujita Toshio
Publication year - 2003
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.10080
Subject(s) - absorbance , reagent , chemistry , thio , substrate (aquarium) , hydrolysis , enzyme , nitrophenol , chromatography , detection limit , medicinal chemistry , biochemistry , organic chemistry , catalysis , oceanography , geology
2,4‐Dinitrophenyl‐1‐thio N ‐acetyl‐β‐ D ‐glucosaminide was examined as a new substrate for analyzing the level of N ‐acetyl‐β‐ 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‐β‐ 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. J. Clin. Lab. Anal. 17:127–131, 2003. © 2003 Wiley‐Liss, Inc.