Figure 1 - A, HPLC elution profile of atrium natriuretic peptide (ANP)(5-28) products after hydrolysis by a purified liver metalloendopeptidase. The substrate (20 nmol) was incubated with 15 Ál of the purified enzyme in a final volume of 30 Ál 50 mM Tris-HCl buffer, pH 7.5, for 30 min at 37oC. The reaction was stopped by heating the mixture at 100oC for 5 min followed by centrifugation at 10,000 g for 10 min. The supernatant fraction was injected into an HPLC column (Nucleosyl 5 Ám C18 145 x 4.5 mm) eluted with a 0-50% gradient of acetonitrile containing 0.05% TFA over a period of 35 min at a flow rate of 1 ml/min. Fragments were identified by amino acid composition: 1 and 2 are the 26-28 and 5-25 fragments of ANP(5-28), respectively. B, HPLC elution profile of bradykinin (BK) products after hydrolysis by purified liver metalloendopeptidase. The substrate (20 nmol) was incubated with 15 Ál of the purified enzyme in a final volume of 30 Ál 50 mM Tris-HCl buffer, pH 7.5, for 30 min at 37oC. The reaction was stopped by heating the mixture at 100oC for 5 min followed by centrifugation at 10,000 g for 10 min. The supernatant fraction was injected into an HPLC column (Nucleosyl 5 Ám C18 145 x 4.5 mm) eluted with a 2-30% gradient of acetonitrile containing 0.05% TFA over a period of 35 min at a flow rate of 1 ml/min. Fragments were identified by amino acid composition: 1 and 2 are the R-P-P-G and F-S-P-F-R fragments of BK, respectively.