Determination of enteropeptidase activity in human duodenal aspirates.
A sensitive procedure is described for the determination in duodenal aspirates of enteropeptidase activity based on the activation of trypsinogen and the estimation of trypsin formed with benzoyl-arginine-p-nitroanilide. Using the recovery approach where a known amount of purified human enteropeptidase is diluted in duodenal fluid and the recoverable activity determined, this method was shown to give a sensitive and reliable estimate of the enteropeptidase activity in duodenal fluid although it was shown that the enzyme was subject to a 10% activation by components in the duodenal fluid. The reported 5-fold stimulation of enteropeptidase activity by bile salts could not be demonstrated.
D002118:Calcium; D004386:Duodenum / Q000201:enzymology*; D010450:Endopeptidases / Q000378:metabolism*; D004765:Enteropeptidase / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism
D010450:Endopeptidases; D014357:Trypsin; D004765:Enteropeptidase; D002118:Calcium