title: CRLI induces vascular smooth muscle relaxation and suggests a dual mechanism of eNOS activation by legume lectins via muscarinic receptors and shear stress.
abstract: Lectins are proteins able to recognize carbohydrates, without modifying their structure, via the carbohydrate-recognition domain (CRD). Here, the three-dimensional structure of the mannose-binding lectin isolated from Cymbosema roseum (CRLI) was determined with X-man molecule modeled into the carbohydrate recognition domain. CRLI relaxant activity in thoracic rat aorta was also investigated, and based on the results, a molecular docking of CRLI with heparan sulfate was performed to investigate the possible interaction with mechanoreceptors involved in vasorelaxation. CRLI (IC₅₀=12.4 μg mL(-)(1)) elicited vasorelaxant response (96%) in endothelialized rat aorta contracted with phenylephrine. Endothelium-derived relaxant factors, extracellular calcium (Ca(2+)e) and muscarinic receptors were also evaluated as putative participants in the CRLI relaxant effect. CRLI relaxant effect was blocked by L-NAME, a nonselective inhibitor of nitric oxide synthase (NOS), and partially inhibited in a calcium-free solution (0Ca) and by atropine, but it remained unchanged in the presence of indomethacin and TEA. In summary, our data suggest interaction between CRLI and muscarinic receptors located in vascular endothelial cells leading to NOS activation triggered by a mechanism that involves Ca(2+)e along with the ability of CRLI to interact with heparan sulfate, a highly rated mechanoreceptor involved in eNOS activation.
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Bruno A M
authors.initials: BA
authors.lastname: Rocha
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Ito L
authors.initials: IL
authors.lastname: Barroso-Neto
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil; Departamento de Ciências Biológicas, Universidade Regional do Cariri, Campos Sales, Brazil.
authors.forename: Claudener S
authors.initials: CS
authors.lastname: Teixeira
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Mayara Q
authors.initials: MQ
authors.lastname: Santiago
authors.affiliation: Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
authors.forename: Alana F
authors.initials: AF
authors.lastname: Pires
authors.affiliation: Instituto Nacional de Pesquisas da Amazônia-INPA, Manaus, Amazonas, Brazil.
authors.forename: Luiz A G
authors.initials: LA
authors.lastname: Souza
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Kyria S
authors.initials: KS
authors.lastname: Nascimento
authors.affiliation: Biomol-Mar, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Fortaleza, Brazil.
authors.forename: Alexandre H
authors.initials: AH
authors.lastname: Sampaio
authors.affiliation: Departamento de Biologia Molecular, Universidade Federal da Paraíba, João Pessoa, Brazil. Electronic address: pldelatorre@gmail.com.
authors.forename: Plinio
authors.initials: P
authors.lastname: Delatorre
authors.affiliation: Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
authors.forename: Ana M S
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 S
authors.initials: BS
authors.lastname: Cavada
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007887:Fabaceae / Q000737:chemistry*; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D037601:Mannose-Binding Lectin / Q000737:chemistry / Q000494:pharmacology*; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004791:Enzyme Inhibitors; D037601:Mannose-Binding Lectin; D010940:Plant Proteins; D011976:Receptors, Muscarinic; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin
keywords: Endothelial cell; Heparan sulfate; Lectin; Molecular docking; Nitric oxide; Protein crystallography