title: Characterization of angiotensin I-converting enzyme from anterior gills of the mangrove crab Ucides cordatus.
abstract: Angiotensin I-converting enzyme (ACE) is a well-known metallopeptidase that is found in vertebrates, invertebrates and bacteria. We isolated from the anterior gill of the crab Ucides cordatus an isoform of ACE, here named crab-ACE, which presented catalytic properties closely resembling to those of mammalian ACE. The enzyme was purified on Sepharose-lisinopril affinity chromatography to apparent homogeneity and a band of about 72 kDa could be visualized after silver staining and Western blotting. Assays performed with fluorescence resonance energy transfer (FRET) selective ACE substrates Abz-FRK(Dnp)P-OH, Abz-SDK(Dnp)P-OH and Abz-LFK(Dnp)-OH, allowed us to verify that crab-ACE has hydrolytic profile very similar to that of the ACE C-domain. In addition, we observed that crab-ACE can hydrolyze the ACE substrates, angiotensin I and bradykinin. The enzyme was strongly inhibited by the specific ACE inhibitor lisinopril (Ki of 1.26 nM). However, in contrast to other ACE isoforms, crab-ACE presented a very particular optimum pH, being the substrate Abz-FRK(Dnp)-P-OH hydrolyzed efficiently at pH 9.5. Other interesting characteristic of crab-ACE was that the maximum hydrolytic activity was reached at around 45°C. The description of an ACE isoform in Ucides cordatus is challenging and may contribute to a better understanding of the biochemical function of this enzyme in invertebrates.
authors.affiliation: Departamento de Informática em Saúde, Universidade Federal de São Paulo, Rua Botucatu 862, São Paulo, SP, Brazil. Electronic address: bersanetti@unifesp.br.
authors.forename: Patrícia A
authors.initials: PA
authors.lastname: Bersanetti
authors.affiliation: Departamento de Informática em Saúde, Universidade Federal de São Paulo, Rua Botucatu 862, São Paulo, SP, Brazil.
authors.forename: Regina F
authors.initials: RF
authors.lastname: Nogueira
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, SP, Brazil.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Marcondes
authors.affiliation: Departamento de Informática em Saúde, Universidade Federal de São Paulo, Rua Botucatu 862, São Paulo, SP, Brazil.
authors.forename: Paulo B
authors.initials: PB
authors.lastname: Paiva
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, SP, Brazil.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Juliano
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, SP, Brazil.
authors.forename: Luiz
authors.initials: L
authors.lastname: Juliano
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, SP, Brazil.
authors.forename: Adriana K
authors.initials: AK
authors.lastname: Carmona
authors.affiliation: Departamento de Fisiologia, Universidade de São Paulo, Rua do Matão, Travessa 14, n 321, São Paulo, SP, Brazil.
authors.forename: Flavia P
authors.initials: FP
authors.lastname: Zanotto
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D003386:Brachyura / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D004795:Enzyme Stability / Q000187:drug effects; D005880:Gills / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D017706:Lisinopril / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D017706:Lisinopril; D007703:Peptidyl-Dipeptidase A
keywords: ACE isoform; Characterization; Crab gill; FRET peptides