title: Lectin from Phaseolus acutifolius var. escumite: chemical characterization, sugar specificity, and effect on human T-lymphocytes.
abstract: Purification of the lectin from Phaseolus acutifolius var. escumite was achieved by affinity chromatography on a column containing glutaraldehyzed membranes from blood group O erythrocytes. The lectin is a tetrameric glycoprotein of 121 kDa with 10% of sugar by weight composed by four subunits of 30 kDa as determined by SDS-PAGE. The lectin is composed of four isolectins as determined by ion-exchange chromatography on a mono-S column. The lectin and its isolectins showed identical NH2 terminal residues (ANDLSFNFQR FNETN) with homology to the PHA leucoagglutinin-precursor. Peptide mass fingerprint from each lectin isoform determined from tryptic peptides by MALDI-TOF (matrix assisted laser desorption ionization-time-of-flight) showed differences among subunits, thus suggesting microheterogeneity in their amino acid sequences or different glycosylation patterns. The lectin and its four isolectins agglutinated erythrocytes without serological specificity and showed mitogenic activity on human leukocytes; moreover, the main effect was rather toward CD8+ than to CD4+ human peripheral lymphocytes. The lectin from escumite was not inhibitable by simple sugars; however, the specificity of the lectin and its isoforms was mainly addressed toward galactose residues present in bi- or triantennary N-acetyllactosamine-type glycans.
authors.affiliation: Laboratorio de Oncología Experimental, Instituto Nacional de Pediatría, 04530 Mexico.
authors.forename: Adriana
authors.initials: A
authors.lastname: Castillo-Villanueva
authors.forename: Heriberto
authors.initials: H
authors.lastname: Caballero-Ortega
authors.forename: Fikrat
authors.initials: F
authors.lastname: Abdullaev-Jafarova
authors.forename: Yonathan
authors.initials: Y
authors.lastname: Garfias
authors.forename: Maria
authors.initials: M
authors.lastname: del Carmen Jiménez-Martínez
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bouquelet
authors.forename: Gisela
authors.initials: G
authors.lastname: Martínez
authors.forename: Guillermo
authors.initials: G
authors.lastname: Mendoza-Hernández
authors.forename: Edgar
authors.initials: E
authors.lastname: Zenteno
mesh_terms: D000595:Amino Acid Sequence; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry*; D002455:Cell Division / Q000187:drug effects; D005690:Galactose / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000737:chemistry*; D037121:Plant Lectins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D017385:Sequence Homology; D013601:T-Lymphocytes / Q000187:drug effects*
chemical_list: D002241:Carbohydrates; D037121:Plant Lectins; D005690:Galactose