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Molecular Characterization and Tandem Mass Spectrometry of the Lectin Extracted from the Seeds of Dioclea sclerocarpa Ducke

Lectin from the seeds of Dioclea sclerocarpa (DSL) was purified in a single step by affinity chromatography on a Sephadex G-50 column. The primary sequence, as determined by tandem mass spectrometry, revealed a protein with 237 amino acids and 81% of identity with ConA. DSL has a molecular mass of 2...

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Detalles Bibliográficos
Autores principales: Correia, Jorge Luis Almeida, do Nascimento, Antônia Sâmia Fernandes, Cajazeiras, João Batista, Gondim, Ana Cláudia Silva, Pereira, Ronniery Ilario, de Sousa, Bruno Lopes, da Silva, André Luiz Coelho, Garcia, Wanius, Teixeira, Edson Holanda, do Nascimento, Kyria Santiago, da Rocha, Bruno Anderson Matias, Nagano, Celso Shiniti, Sampaio, Alexandre Holanda, Cavada, Benildo Sousa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6264274/
https://www.ncbi.nlm.nih.gov/pubmed/22037666
http://dx.doi.org/10.3390/molecules16119077
Descripción
Sumario:Lectin from the seeds of Dioclea sclerocarpa (DSL) was purified in a single step by affinity chromatography on a Sephadex G-50 column. The primary sequence, as determined by tandem mass spectrometry, revealed a protein with 237 amino acids and 81% of identity with ConA. DSL has a molecular mass of 25,606 Da. The β and γ chains weigh 12,873 Da and 12,752 Da, respectively. DSL hemagglutinated rabbit erythrocytes (both native and treated with proteolytic enzymes), showing stability even after one hour of exposure to a specific pH range. The hemagglutinating activity of DSL was optimal between pH 6.0 and 8.0, but was inhibited after incubation with D-galactose and D-glucose. The pure protein possesses a molecular mass of 25 kDa by SDS-PAGE and 25,606 Da by mass spectrometry. The secondary structure content was estimated using the software SELCON3. The results indicate that b-sheet secondary structures are predominant in DSL (approximately 42.3% antiparallel b-sheet and 6.7% parallel b-sheet). In addition to the b-sheet, the predicted secondary structure of DSL features 4.1% a-helices, 15.8% turns and 31.3% other contributions. Upon thermal denaturation, evaluated by measuring changes in ellipticity at 218 nm induced by a temperature increase from 20 °C to 98 °C, DSL displayed cooperative sigmoidal behavior with transition midpoint at 84 °C and permitted the observation of two-state model (native and denatured).