Lens culinaris lectin or agglutinin (LCA) is isolated from Lens culinaris (lentil) seeds and purified by affinity chromatography. The lectin has two subunits and a molecular weight of 46 kDa and it forms a complex together with sucrose. Lectins are, due to their specific binding to carbohydrate struc- tures on the cell surface or elsewhere useful in haematology, immunology or as specific markers for membrane glycoprotein structures. LCA’s carbohydrate specificity is D-mannose and D-glucose and the two isomers LCA-A and LCA-B agglutinates human red blood cells, although this reaction is not blood group specific. LCA is also a useful component in affinity chroma- tography columns for the separation of glycoconjugates. Lens culinaris lectin is supplied as a white lyophilized powder from 1 mM CaCl2, 1 mM MnCI2 and 1 mM MgCI2. No preservatives are added. In isoelectric focusing, the lectin generates two major bands at pI 8.15, 8.45 and one minor band at pI 8.65. The activity of the lectin is determined by haemagglutination with human blood. Lens culinaris lectin agglutinates a 2% suspension of human erythrocytes at a lectin concentration of ≤8 μg/ml in 0.9% saline solution (NaCl) after 2 h at 25°C. Adding 60 mM methylmannoside yields an inhibition with a lectin titer that is at least 16-fold weaker than the control.Addition of Mn2+ and Ca2+ to the reconstitution buffer will enhance hemagglutination activity.
Lens culinaris lyophilized lectin may be reconstituted with 2 ml of deionized water before use, spin the vial gently until full dissolution. Aggregation is thought to occur in the presence of high concentrations of 2-mercaptoethanol.
Haemagglutination studies;Cell agglutination studies;Component in affinity columns;Separation of glycoconjugates