title: An automated continuous flow procedure for the determination of enterokinase.
abstract: A continuous flow method has been developed for the automatic determination of enterokinase in rat small intesstine mucosa and/or luminal content. Trypsinogen was first hydrolysed by enterokinase under conditions which minimize autocatalytic activation. L-benzoyl-arginine paranitroanilide was then added and split to paranitroaniline by the trypsin so formed. Liberated paranitroalinine was diazotized and converted by the Bratton-Marshall reagent (N-naphthyl ethylene diamine) to an azodye, with maximum absorption at 550 nm. This method of determination was found to be six times more sensitive than the direct p-nitroaniline determination method. 36 determinations can be made hourly.
mesh_terms: D000818:Animals; D001322:Autoanalysis; D001647:Bile Acids and Salts / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D004796:Clinical Enzyme Tests / Q000379:methods*; D010450:Endopeptidases / Q000032:analysis*; D004765:Enteropeptidase / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology; D051381:Rats
chemical_list: D001647:Bile Acids and Salts; D010450:Endopeptidases; D004765:Enteropeptidase; D002118:Calcium