title: Purification, biochemical characterization, and bioactive properties of a lectin purified from the seeds of white tepary bean (phaseolus acutifolius variety latifolius).
abstract: The present work shows the characterization of Phaseolus acutifolius variety latifolius, on which little research has been published, and provides detailed information on the corresponding lectin. This protein was purified from a semi-domesticated line of white tepary beans from Sonora, Mexico, by precipitation of the aqueous extract with ammonium sulfate, followed by affinity chromatography on an immobilized fetuin matrix. MALDI TOF analysis of Phaseolus acutifolius agglutinin (PAA) showed that this lectin is composed of monomers with molecular weights ranging between 28 and 31 kDa. At high salt concentrations, PAA forms a dimer of 63 kDa, but at low salt concentrations, the subunits form a tetramer. Analysis of PAA on 2D-PAGE showed that there are mainly three types of subunits with isoelectric points of 4.2, 4.4, and 4.5. The partial sequence obtained by LC/MS/MS of tryptic fragments from the PAA subunits showed 90-100% identity with subunits from genus Phaseolus lectins in previous reports. The tepary bean lectin showed lower hemagglutination activity than Phaseolus vulgaris hemagglutinin (PHA-E) toward trypsinized human A and O type erythrocytes. The hemagglutination activity was inhibited by N-glycans from glycoproteins. Affinity chromatography with the immobilized PAA showed a high affinity to glycopeptides from thyroglobulin, which also has N-glycans with a high content of N-acetylglucosamine. PAA showed less mitogenic activity toward human lymphocytes than PHA-L and Con A. The cytotoxicity of PAA was determined by employing three clones of the 3T3 cell line, demonstrating variability among the clones as follows: T4 (DI₅₀ 51.5 µg/mL); J20 (DI₅₀ 275 µg/mL), and N5 (DI₅₀ 72.5 µg/mL).
authors: Institute of Health Sciences, Universidad Autónoma del Estado de Hidalgo, Ex-Hacienda de la Concepción, Tilcuautla, CP 42080 Pachuca de Soto, Hgo, Mexico. m.valadezvega@lycos.com
authors: Carmen
authors: C
authors: Valadez-Vega
authors: Ana María
authors: AM
authors: Guzmán-Partida
authors: Francisco Javier
authors: FJ
authors: Soto-Cordova
authors: Gerardo
authors: G
authors: Alvarez-Manilla
authors: José A
authors: JA
authors: Morales-González
authors: Eduardo
authors: E
authors: Madrigal-Santillán
authors: José Roberto
authors: JR
authors: Villagómez-Ibarra
authors: Clara
authors: C
authors: Zúñiga-Pérez
authors: José
authors: J
authors: Gutiérrez-Salinas
authors: Marco A
authors: MA
authors: Becerril-Flores
mesh_terms: D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D037102:Lectins / Q000302:isolation & purification*; D027805:Phaseolus / Q000737:chemistry* / Q000196:embryology; D012639:Seeds / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D037102:Lectins