title: Vasorelaxant activity of Canavalia grandiflora seed lectin: A structural analysis.
abstract: Lectins are comprised of a large family of proteins capable of the specific and reversible recognition of carbohydrates. Legume lectins, the most studied plant lectins, show high structural similarity, but with modifications that imply a variation in the intensity of some biological activities. In this work, the primary and tertiary structures of Canavalia grandiflora (ConGF) were determined. ConGF, a lectin isolated from C. grandiflora seeds, is able to induce relaxant activity in rat aortic rings. The complete sequence of ConGF comprises 237 amino acids. This particular protein has primary sequence variations commonly found in lectins from Dioclea and Canavalia genera. The protein structure was solved at 2.3 Å resolution by X-ray crystallography. An X-Man molecule was modeled into the carbohydrate recognition domain. Still, ConGF (30 and 100 μg mL(-1)) elicited 25% of vasorelaxation (IC50=34.48 ± 5.07 μg mL(-1)) in endothelialized aortic rings. A nonselective inhibitor of nitric oxide blocked ConGF relaxant effect, showing mediation by nitric oxide. Key distances between ConGF carbohydrate recognition domain residues were determined in order to explain this effect, in turn revealing some structural aspects that could differentiate lectins from the Canavalia genera with respect to different efficacy in vasorelaxant effect.
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Ito Liberato
authors.initials: IL
authors.lastname: Barroso-Neto
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Rafael Conceição
authors.initials: RC
authors.lastname: Simões
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Bruno Anderson Matias
authors.initials: BA
authors.lastname: Rocha
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Maria Julia Barbosa
authors.initials: MJ
authors.lastname: Bezerra
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Francisco Nascimento
authors.initials: FN
authors.lastname: Pereira-Junior
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Vinicius José
authors.initials: VJ
authors.lastname: Silva Osterne
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Kyria Santiago
authors.initials: KS
authors.lastname: Nascimento
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil; Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Celso Shiniti
authors.initials: CS
authors.lastname: Nagano
authors.affiliation: Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Brazil.
authors.forename: Plinio
authors.initials: P
authors.lastname: Delatorre
authors.affiliation: Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
authors.forename: Maria Gonçalves
authors.initials: MG
authors.lastname: Pereira
authors.affiliation: Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
authors.forename: Alana
authors.initials: A
authors.lastname: Freitas Pires
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil; Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Alexandre Holanda
authors.initials: AH
authors.lastname: Sampaio
authors.affiliation: Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
authors.forename: Ana Maria Sampaio
authors.initials: AM
authors.lastname: Assreuy
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil. Electronic address: bscavada@ufc.br.
authors.forename: Benildo Sousa
authors.initials: BS
authors.lastname: Cavada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D066298:In Vitro Techniques; D008297:Male; D008358:Mannose / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D037121:Plant Lectins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D051381:Rats; D017208:Rats, Wistar; D017421:Sequence Analysis; D013329:Structure-Activity Relationship; D014665:Vasodilator Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D037121:Plant Lectins; D014665:Vasodilator Agents; C039268:lectin, Canavalia; D008358:Mannose
keywords: Canavalia grandiflora; ConA-like; Lectin; Structure; Vasorelaxation