title: Biochemical properties of the angiotensin-converting-like enzyme from the leech Theromyzon tessulatum.
abstract: This article reports the evidence and the biochemical properties of an angiotensin-converting (ACE)-like enzyme from head parts of the leech Theromyzon tessulatum. After solubilization from membranes with Triton X-114, the ACE-like enzyme was purified from the detergent-poor fraction. Four steps of purification including gel permeation and anion exchange chromatographies followed by a reversed-phase HPLC were needed. This poor glycosylated peptidyl dipeptidase (of ca. 120 kDa) hydrolyzes, at pH 8.4 and at 37 degrees C, the Phe8-His9 bond of angiotensin I with a high catalytic activity (i.e., K(m): 830 microM and Kcat/K(m): 153 s-1 mM-1). The hydrolysis of angiotensin I is inhibitable at 80% by captopril (IC50 = 175 nM) and lisinopril (IC50 = 35 nM). This activity is strictly dependent on the presence of NaCl and is increased by Zn2+. This zinc metallopeptidase also attacks peptides that have in their sequence either Gly-His, Gly-Phe, or Phe-His bond [e.g., enkephalins (Kcat/K(m): 12 s-1 mM-1) or bradykinin (Kcat/K(m): 2200 s-1 mM-1]. Taken together, these arguments are consistent with an ACE-like activity implicated in metabolism of angiotensins and bradykinin in leeches.
authors.affiliation: Centre de biologie cellulaire, Laboratoire de Phylogénie moléculaire des Annélides, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
authors.forename: V
authors.initials: V
authors.lastname: Laurent
authors.forename: M
authors.initials: M
authors.lastname: Salzet
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D016308:Enkephalin, Leucine-2-Alanine / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006020:Glycopeptides / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007865:Leeches / Q000201:enzymology*; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D007703:Peptidyl-Dipeptidase A / Q000302:isolation & purification / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D006020:Glycopeptides; D008565:Membrane Proteins; D010446:Peptide Fragments; D011480:Protease Inhibitors; D012965:Sodium Chloride; D016308:Enkephalin, Leucine-2-Alanine; D002216:Captopril; D007703:Peptidyl-Dipeptidase A; C008890:phosphoramidon