Purification and carbohydrate-binding characterization of arundo donax lectin

ZANETTI GD, SENDRA VG, TRINDADE MV, NORES GA, IRAZOQUI FJ, VOZARI-HAMPE, MM

Pinamar, Argentina

Congreso; SAIB 41-X Congress Panamerican Association for Biochemistry and Molecular Biology (PABMB); 2005

PURIFICATION AND CARBOHYDRATE-BINDING CHARACTERIZATION OF ARUNDO DONAX LECTIN Zanetti, Gilberto D; a Sendra, Victor G; b Trindade, Vera M; a Nores, Gustavo A; b Irazoqui, Fernando J; b Vozari-Hampe, Magdolna M. a aDepartment of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. bDepartment of Biological Chemistry, Faculty of Chemical Sciences, National University of Cordoba, Argentina. E-mail: hampe@orion.ufrgs.br Glycans are key structures involved in biological processes such as cell attachment, migration and invasion. Information coded on cell-surface glycans is frequently deciphered by proteins, as lectins, that recognize specific carbohydrate topology. Here, we describe the purification and carbohydrate specificity of Arundo donax lectin (ADL). ADL was purified by affinity chromatography using rabbit erythrocytic stroma incorporated into a polyacrylamide gel. Elution of lectin was carried out with NH4OH. The purity of ADL was controlled by polyacrylamide electrophoresis (SDS-PAGE), yielding a single proteic band of approximately 35 kDa. ADL shows hemagglutinating activity with blood red cells from rabbit, pork and rat. GlcNAc and related GlcNAc molecules are the more important inhibitors of hemagglutinating activity of ADL. N-acetyl and equatorial C4-hydroxyl residues from GlcNAc are important loci in the carbohydrate-binding recognition of ADL. Adjacent hydrophobic group to GlcNAc, such as alpha benzyl, also shows a partial contribution in the interaction. ADL shows ability in binding to HT29 and T47D human epithelial tumor cells by direct lectin fluorescence. ADL could be a useful tool in detection of GlcNAc glycoconjugates, with potential application in oncology area.