Concanavalin A

• UniProt: P02866

Concanavalin A ( Con A short ) is a protein from the jack bean ( Canavalia ensiformis ) and belongs to the group of lectins, since it can bind carbohydrates, especially α -D-glucose and other sugars, without exhibiting enzymatic activity.

The concanavalin monomer consists of 237 amino acids and contains structure-building manganese and calcium. The presence of these metal ions causes Con A is able to bind carbohydrates. At neutral pH ( 7 ) it is deposited together into a tetramer in the acidic pH range, it decomposes to form a dimer. Since it occurs mainly in the seeds of sword bean and is very stable, it is likely this plant as a storage protein.

Use

By the ability to bind specific carbohydrates, Con A is widely used in biochemistry, it clots, for example, cancer cells, while normal cells are not aggregated. On chromatography -applied ( immobilized Con A) is used for the purification of glycoproteins and carbohydrates.

In the immunological research Con A is used as a mitogen that stimulates T- lymphocytes; The effect is probably due to activation of the T cells via the CD3 - complex. However, it also stimulates B cells to proliferate.

Historical

Concanavalin A was next urease one of the first proteins - could be purified and crystallized (see also: Protein crystal) - around 1930, James Batcheller Sumner was awarded the 1946 Nobel Prize in Chemistry. The crystal structure analysis with the determination of the atomic positions of the protein was achieved only from 1975.