Concanavalin A from Canavalia ensiformis (Jack bean)

Concanavalin A (con A) is a plant lectin refined from jack beans. It is a tetrameric protein, which has four identical 28 kDa subunits. Con A has the ability to connect with the mannose residues of several glycoproteins and can stimulate lymphocytes.

Concanavalin A from Canavalia ensiformis (Jack bean) has been used:

• as T-lymphocyte mitogen in lymphocyte proliferation assay for correlations with organochlorine contaminants (OCs)
• for in vitro stimulation of T cell hybridomas, BW5147 cells and primary CD4⁺ T cells for T cell vaccination and for induction of hepatitis
• for the stimulation of mice splenocytes in the suppression of T-lymphocytes proliferation assay
• for the stimulation of spleen in mitogen assays

Con A is not blood group specific but has an affinity for terminal α-D-mannosyl and α-D-glucosyl residues. Ca²⁺ and Mn²⁺ ions are required for activity. Con A dissociates into dimers at pH 5.6 or below. Between pH 5.8 and pH 7.0, Con A exists as a tetramer; above pH 7.0 higher aggregates are formed. Con A exhibits mitogenic activity which is dependent on its degree of aggregation. Succinylation results in an active dimeric form which remains a dimer above pH 5.6.

Highly purified by specific affinity chromatography

Where reported, agglutination activity is expressed in μg/ml and is determined from serial dilutions in phosphate buffered saline, pH 6.8, containing Ca²⁺ and Mn²⁺ of a 1 mg per mL solution. This activity is the lowest concentration to agglutinate a 2% suspension of human erythrocytes after 1 hr incubation at 25 °C.