Human calpain 1 has been used in a study to assess how the crystal structures of human calpains 1 and 9 imply diverse mechanisms of action and auto-inhibition. Human calpain 1 has also been used in a study to investigate the synthesis, biological evaluation and molecular modelling of N-heterocyclic dipeptide aldehydes as selective calpain inhibitors.
Caplain 1 is a neutral calcium-dependent cysteine protease containing the EF-hand motif. The protease consists of two subunits; the larger subunit has four domains that are homologous with papain and calmodulin. The smaller subunit has one domain that shares homology with calmodulin. It is activated by micromolar levels of calcium and hence, it is also called as micro-calpain. Its activation leads to cellular protein degradation, neuronal cell degeneration, and autoimmune demyelinating diseases such as multiple sclerosis.
