Concanavalin A
| Concanavalin A ( Canavalia ensiformis ) | ||
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| Structure of the Concanavalin A | ||
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Existing structural data: s. UniProt |
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| Mass / length primary structure | 237 amino acids | |
| Secondary to quaternary structure | Homotetramer | |
| Cofactor | Ca 2+ , Mn 2+ | |
| Identifier | ||
| External IDs | ||
Concanavalin A ( Con A for short ) is a protein from the jack bean ( Canavalia ensiformis ) and belongs to the group of lectins , as it can bind carbohydrates , in particular α- D- glucose and similar sugars, without having any enzymatic activity.
The concanavalin monomer consists of 237 amino acids and contains structure- forming manganese and calcium . The presence of these metal ions means that Con A is able to bind carbohydrates. At a neutral pH value (around 7) it forms a tetramer , at an acidic pH range it breaks down into a dimer . Since it occurs primarily in the seeds of the sword bean and is very stable, it probably serves as a storage protein for this plant.
use
Due to its ability to bind certain carbohydrates, Con A is widely used in biochemistry , for example it clumps cancer cells while healthy cells are not aggregated. On chromatography columns applied ( immobilized Con A ) is used to purify glycoproteins and carbohydrates .
In immunological research, Con A is used as a mitogen that stimulates T lymphocytes ; the effect presumably takes place through activation of the T cells via the CD3 complex. However, it also stimulates B lymphocytes to proliferate .
Historical
Concanavalin A was, along with urease, one of the first proteins that could be purified and crystallized around 1930 ( see also: protein crystal ); for this, James Batcheller Sumner received the Nobel Prize in Chemistry in 1946. The crystal structure analysis with the determination of the atomic positions of the protein was only possible from 1975.
literature
- TK Chowdhury, AK Weiss (ed.): Concanavalin A . Plenum Press, New York, 1975