N-acetyl-β-D-glucosaminidase (NAG)
For the in vitro quantitative determination of NAG activity in urine.
NAG is a lysosomal enzyme involved in the breakdown metabolism of glycoproteins. Increased NAG levels in urine are an early indication of renal disease and can serve as a valuable renal monitoring test in disorders such as nephritic syndrome, glomerulunephritis, drug abuse associated nephrotoxicity, diabetes-associated nephropathy, hypertension and urinary tract infections.
NAG hydrolyses ammonium 5-[4-(2- acetamido-2- deoxy-beta-D-glucopyranosyloxy)-3- methoxyphenylmethylene]- 2-thioxothiazolidin-4-one-3-ethanoate (VRA-GlcNAc), the product formation is detected by development of color at 505 nm upon addition of alkaline buffer.
1. Krishna KS ， Kirubakaran MG ， Pandey AP ， et al.Urinary NAG and AAP in the diagnosis of graft rejection after live donor renal transplantation. Clin Chim Acta，1985，150（2）:69-85.
2. IIstran pocsl et.al. VRA-GlcNAc: novel substrate for N-Acetyl-β-D-glucosaminidase applied to assay of this enzyme in urine.Clinical chemisty, 1990,36(11): 1884-1888