α-L-Fucosidase Assay Kit (AFU)
For the in vitro quantitative determination of AFU in serum or plasma
AFU is a lysosomal enzyme involved in the degradation of a diverse group of naturally-occurring fucoglycoconjugates. Serum AFU activity is considered a useful marker of hepatocellular carcinoma (HCC). Increased AFU levels in serum are an early indication of HCC. Though measurement of serum fetoprotein (AFP) is a common practice for early detection of HCC, AFP assay alone suffers from its low specificity and sensitivity due to the fact that not all HCC secrete AFP. AFP levels may be normal in as many as 40% of patients with early HCC and 15-20% patients with advanced HCC. Recent studies clearly demonstrated that measurements of both AFP and AFU can significantly increase the detection specificity and sensitivity for HCC. AFU is reported to be a more sensitive marker especially for detecting a small tumor size of HCC.
The AFU assay is based on the enzymatic cleavage of the synthetic substrate 2-chloro-4-nitrophenyl-α-Lfucopyranoside toα-L-fucoside and 2-chloro-4-nitrophenol which is quantified by measuring the absorbances at 405nm in a kinetic fashion. It is a one step assay with a single assay reagent. One unit of AFU is defined as the amount of AFU that cleaves one μmole of 2-chloro-4nitrophenyl-α-L-fucoside per min at 37℃.
- Zielke K. et al. Fucosidsis: diagnosis by serum assay of -L-fucosidase. J. Lab. Clin. Med. 79: 164 (1972)