CALPAIN
calpain: translation
Calcium-activated cytoplasmic proteases containing the EF-hand motif. Calpain I is activated by micromolar calcium, Calpain II by millimolar calcium. Calpain has two subunits, the larger (80 kD) has 4 domains one homologous with papain, one with calmodulin, the smaller (30 kD) has one domain homologous with calmodulin. First isolated from erythrocytes, but now described from other cells.