Presence and biochemical properties of a molluscan invertebrate angiotensin-converting enzyme.
A soluble 65582.9 Da (in MALDI-TOF) angiotensin converting (ACE)-like enzyme has been purified by a captopril-Sepharose affinity column chromatography from the mollusk Mytilus edulis. This glycosylated peptidyl dipeptidase, with an N-terminal sequence of LDPELSPGCFVANQAGGQLF, hydrolyses the Phe8-His9 bond (at pH 8.4 and 37 degrees C) of angiotensin I with a high catalytic activity i.e. Km: 168 microM and Kcat/Km: 262 s-1 mM-1. The hydrolysis of angiotensin I is inhibited by the specific ACE inhibitors captopril and lisonopril (Ic50 = 50 nM). This activity is increased by Cl- (optimal Cl- concentration 400 mM) and by Zn2+. This zinc metallopeptidase also attacks peptides having a Gly-His, Gly-Phe or a Phe-His bond in their sequence e.g. leucine-enkephalin (Kcat/Km: 1200 s-1 mM-1 or bradykinin (Kcat/Km: 2500 s-1 mM-1). Mytilus ACE displays properties of the C-domain of human ACE, indicating a high degree of conservation during evolution. These results are consistent with an ACE activity implicated in metabolism of several neuropeptides in mollusks.
Laurent
V
V
Centre de biologie cellulaire, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
Stefano
G
G
Salzet
M
M
D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D049872:Bivalvia / Q000201:enzymology*; D015153:Blotting, Western; D019143:Evolution, Molecular; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D013379:Substrate Specificity; D013696:Temperature
D000806:Angiotensin-Converting Enzyme Inhibitors; D012965:Sodium Chloride; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A