AnaSpec, EGT Group is pleased to announce the release of two assay kits for
quantitating enterokinase enzymatic activity – the SensoLyte®
520 and SensoLyte®
Rh110 Enterokinase Activity Assay Kits. The former is a FRET (fluorescence
resonance energy transfer)-based assay employing a novel internally quenched
5-FAM/QXL™ 520 substrate and the latter, an internally quenched
fluorimetric peptide substrate. Both substrates emit at 520 nm with excitation
at 490 nm. At the long emission wavelength of 520 nm, autofluorescence of components
in biological samples and test compounds is minimal, thus making the kits ultra-sensitive.
Assays are performed in a convenient 96-well microplate format.
Enterokinase or enteropeptidase
is a heterodimeric serine protease produced by cells in the duodenal wall. It
converts trypsinogen to trypsin, indirectly activating a number of pancreatic
digestive enzymes.1,2 Enterokinase is a key enzyme for intestinal digestion of proteins. Its deficiency
may cause severe protein malabsorption leading to impaired development and growth.3 Enterokinase also plays an important role in acute experimental
and clinical pancreatitis.4 The high degree of specificity exhibited
by enteropeptidase for cleaving affinity or other tags from recombinant proteins
makes it an ideal tool for use in biochemical applications.5,6
Figure 1. Sensitivity of the SensoLyte®
520 Enterokinase assay has been tested using serial dilution of
bovine enterokinase. 5-FAM/QXL™ 520 FRET substrate was incubated with
the indicated amount of enzyme and fluorescence was measured after 1 hour (FlexStation
384II, Molecular Devices). The assay can detect as low as 1.25 ng/mL of active
Figure 2. Inhibition of enterokinase activity by E-64 was measured with SensoLyte®520
Enterokinase Activity Assay Kit.
Related Products and Services
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1. Light, A., and Janska, H. Trends Biochem Sci 14, 110 (1989).
2. Zheng, XL., et al. Front Biosci (Elite Ed.) 1, 242 (2009).
3. Antonowicz, I., Ciba Found Symp 70, 169 (1979).
4. Mann, NS. and Mann, SK. Proc Soc Exp Biol Med 206, 114 (1994).
5. Forsberg, G. et al. J Protein Chem 11, 201 (1992).
6. Wang, Z. et al. Biol Chem 379, 167 (1998).