Heder G, Böttger A, Siems W E, Halatsch W R, Steinmann C
Institut für Wirkstofforschung, Akademie der Wissenschaften der DDR, Berlin-Friedrichsfelde.
Pharmazie. 1988 Sep;43(9):637-9.
The simple determination of the Neutral Metalloendopeptidase (NEP, Enkephalinase A) with the known fluorogenic substrate Dansyl-D-Ala-Gly-(pNO2)Phe-Gly is disturbed by high concentrations of the Angiotensin-Converting-Enzyme (ACE). ACE hydrolyzes this substrate too but to a smaller degree. In some tissues and body fluids a further substrate hydrolysis takes place by any indefinite proteases. Finally the enzymatic hydrolysis of the NEP-substrate is inhibited by phosphate ions. A method is proposed for the elimination of this disturbances in the NEP-determination with a phosphate-free buffer using two comparison tests with Lisinopril and o-Phenanthroline. The resulting NEP-activity is calculated very simple thereafter.
