Ruffet E Paquet N Frutiger S Hughes GJ Jaton JC 1992 The 133-amino-acid sequences of the alpha-subunit of jacalin (a lectin from Artocarpus integrifolia) and of the slightly larger alpha'-subunit were determined. The alpha'- and alpha-subunits, in the approximate ratio of 1:3, were found to be virtually identical in their primary structures, except for one valine for isoleucine substitution at position 113. Although both alpha'- and alpha-chains were glycosylated, the extent of glycosylation in the alpha'-chain was much greater than that in the alpha-subunit. In the alpha'-polypeptide, all molecules contained an N-linked oligosaccharide at position 74 and some contained sugar at position 43. The alpha- and alpha'-subunits were found to be strongly non-covalently associated with three distinct beta-subunits containing 20 amino acids each. Electron-microscopic visualization of native jacalin disclosed a structure composed of four alpha-type subunits with a clear-cut 4-fold symmetry. Analytical-ultracentrifugation studies of jacalin revealed an average molecular mass of 65 kDa, a value compatible with a tetrameric structure of the alpha(alpha')-subunits. The recalculated number of sugar-binding sites per jacalin molecule, given a molecular mass of 65 kDa, would yield 0.8 sites per alpha(alpha')-promoter, i.e. about twice the value previously determined [Appukutan & Basu (1985) FEBS Lett. 180, 331-334; Ahmed & Chatterjee (1989) J. Biol. Chem. 264, 9365-9372]. application/pdf https://sonar.ch/global/documents/54611 eng info:eu-repo/semantics/altIdentifier/doi/10.1042/bj2860131 info:eu-repo/semantics/altIdentifier/pmid/1520261 info:eu-repo/semantics/openAccess The Biochemical journal. - 1992 Amino Acid Sequence Carbohydrates Chromatography, High Pressure Liquid Cyanogen Bromide Electrophoresis, Polyacrylamide Gel Lectins Macromolecular Substances Microscopy, Electron Molecular Sequence Data Molecular Weight Peptide Fragments Plant Lectins Plants Structural and electron-microscopic studies of jacalin from jackfruit (Artocarpus integrifolia) show that this lectin is a 65 kDa tetramer. http://purl.org/coar/resource_type/c_6501