Enterokinase (also known as enteropeptidase, EC 3.4.21.9) is a key enzyme that initiates protein digestion in the intestine. It precisely activates trypsinogen to trypsin, which then cascade-activates chymotrypsinogen and procarboxypeptidase. Its expression is specifically localized in differentiated intestinal cells and goblet cells, making it both a core regulator of nutritional digestion and a reliable marker of intestinal epithelial maturation.
The Enterokinase Activity Assay Kit is a rapid method for determining enterokinase activity in biological samples. This method detects enterokinase activity by cleaving a 7-amino-4-trifluoromethylcoumarin (AFC)-labeled peptide substrate containing an enterokinase recognition sequence. The intensity of the fluorescent product AFC (excitation wavelength Ex=380 nm, emission wavelength Em=500 nm) generated by the reaction is proportional to the enzyme activity in the sample.