title: Purification and partial characterization of a novel lectin from Dioclea lasiocarpa Mart seeds with vasodilator effects.
abstract: A lectin from seeds of Dioclea lasiocarpa (DLL) was purified in a single step by affinity chromatography in a Sephadex G-50 column. DLL haemagglutinated rabbit erythrocytes showing stability even after 1 h of exposure to a different pH values (optimal between pH 6.0 and 8.0) but was inhibited after incubation with D-mannose and D-glucose. The pure protein possessed a molecular weight of 25 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 25,410Da by mass spectrometry. The results analyzed by the software SELCON 3 indicate that β-sheet secondary structures are predominant in DLL (approximately 40.2% antiparallel β-sheet, 4.6% parallel β-sheet, 7.2% α-helices, 17.3% turns, and 28.7% unordered structures). Mechanical activity of isolated aorta from rat measured by cumulative concentration curves of DLL, performed at the contraction plateau induced by phenylephrine in either endothelium-intact or denuded aorta. DLL (IC(50)  = 34.12 ± 3.46 µg/ml) relaxed precontracted endothelized aortic rings by 34.61 ± 9.06%, 55.19 ± 11.9%, and 81.33 ± 14.35%, respectively, at 10 µg/ml (initial concentration), 30 µg/ml, and 100 µg/ml (maximum effect). All effects occurred via interaction with lectin domains and participation of nitric oxide.
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas (Biomol-Lab), Department of Biochemistry and Molecular Biology, Federal University of Ceará, Av. Humberto Monte s/n, Bloco 907, Lab. 1075, Campus do Pici, Zip code 60.400-970, Fortaleza, CE, Brazil.
authors.forename: Antônia Sâmia F
authors.initials: AS
authors.lastname: do Nascimento
authors.forename: Ana Cláudia S
authors.initials: AC
authors.lastname: Gondim
authors.forename: João B
authors.initials: JB
authors.lastname: Cajazeiras
authors.forename: Jorge Luis A
authors.initials: JL
authors.lastname: Correia
authors.forename: Alana de F
authors.initials: Ade F
authors.lastname: Pires
authors.forename: Kyria S
authors.initials: KS
authors.lastname: do Nascimento
authors.forename: André Luis C
authors.initials: AL
authors.lastname: da Silva
authors.forename: Celso S
authors.initials: CS
authors.lastname: Nagano
authors.forename: Ana Maria S
authors.initials: AM
authors.lastname: Assreuy
authors.forename: Benildo S
authors.initials: BS
authors.lastname: Cavada
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D002478:Cells, Cultured; D052598:Dioclea / Q000737:chemistry*; D004355:Drug Stability; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology; D009924:Organ Culture Techniques; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D037121:Plant Lectins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012639:Seeds / Q000737:chemistry*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D010936:Plant Extracts; D037121:Plant Lectins; D014665:Vasodilator Agents