Purification and characterization of a lectin from seeds of Vatairea macrocarpa Duke

• Autor(a) principal: Cavada, Benildo S.
• Data de Publicação: 1998
• Outros Autores: Santos, Cláudia F., Grangeiro, Thalles B., Nunes, Edson P., Sales, Patricia V. P., Ramos, Ronaldo L., Sousa, Flávia A. M. de, Crisostomo, Clebia V., Calvete, Juan J.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/64278
• topic: Vatairea macrocarpa; Leguminosae; Lectin; Affinity chromatography; D-galactose-binding; Amino acid sequence

The protein, a galactose binding lectin made up of a misture of full length chains and endogenous C- and N-terminal fragments, was purified from Vatairea macrocarpa seeds and its properties were studied. A lectin from Vatairea macrocarpa Duke seeds (VML) was isolated using affinity chromatography on a guar gum column. The lectin, a glycoprotein without erythrocyte specificity, displays specificity to galactose and some derivatives. On SDS-polyacrylamide gels, V. macrocarpa seed lectin is composed of two major high-Mr bands of 34 and 32 kDa and two minor low-Mr bands of 22 and 13 kDa. N-Terminal sequencing showed that the 34, 32, and 13 kDa products possess identical N-terminal sequence, which display best similarity with the N-terminal portion of Robinia pseudoacacia lectins (RPL). On the other hand, the N-terminal sequence of the 22 kDa band can be aligned with an internal sequence of RPL starting at residue 149 of the cDNA-derived sequence. These data indicate that, like other leguminous lectins, VML is made up of a mixture of onechain 30–35 kDa glycoforms and of 22 and 13 kDa endogenous C- and N-terminal fragments. Size-exclusion chromatography indicated that, at neutral pH, VML is predominantly a dimeric (70 kDa) protein, although tetramers (115 kDa) and larger aggregates (300 kDa) were also present.