The endopeptidase activity and the activation by Cl− of angiotensin-converting enzyme is evolutionarily conserved: purification and properties of an an angiotensin-converting enzyme from the housefly, Musca domestica

• DOI: 10.1042/bj3140639
• Publication Date: 2015-08-10T21:47:57Z
• Authors: Nazarius S. LAMANGO; Mohammed SAJID; R. Elwyn ISAAC
• Keywords: 0303 health sciences; Hydrolysis; Molecular Sequence Data; Angiotensin-Converting Enzyme Inhibitors; Peptidyl-Dipeptidase A; Sodium Chloride; Biological Evolution; Chromatography, Affinity; 3. Good health; Enzyme Activation; Gonadotropin-Releasing Hormone; 03 medical and health sciences; Houseflies; Endopeptidases; Animals; Amino Acid Sequence; Peptides; Conserved Sequence

A soluble 67 kDa angiotensin-converting enzyme (ACE) has been purified by lisinopril-Sepharose affinity column chromatography from adult houseflies, Musca domestica. The dipeptidyl carboxypeptidase activity towards benzoyl-Gly-His-Leu was inhibited by captopril (IC50 50 nM) and fosinoprilat (IC50 251 nM), two inhibitors of mammalian ACE, and was activated by Cl- (optimal Cl- concentration 600 mM). Musca ACE removed C-terminal dipeptides from angiotensin I, bradykinin, [Leu5]enkephalin and [Met5]enkephalin and also functioned as an endopeptidase by hydrolysing dipeptideamides from [Leu5]enkephalinamide and [Met5]enkephalinamide, and a dipeptideamide and a tripeptideamide from substance P. Musca ACE was also able to cleave a tripeptide from both the N-terminus and C-terminus of luteinizing hormone-releasing hormone, with C-terminal hydrolysis predominating. Maximal N-terminal tripeptidase activity occurred at 150 mM NaCl, whereas the C-terminal tripeptidase activity continued to rise with increasing concentration of Cl- (0–0.5 M). Musca ACE displays properties of both the N- and C-domains of human ACE, indicating a high degree of conservation during evolution of the substrate specificity of ACE and its response to Cl-.