EC - Calpain-3

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IntEnz Enzyme Nomenclature


Accepted name:
Other names:
calpain p94
muscle calpain
calpain 3
calcium-activated neutral proteinase 3
muscle-specific calcium-activated neutral protease 3
calpain L3
Systematic name:




This Ca2+-dependent enzyme is found in skeletal muscle and is genetically linked to limb girdle muscular dystrophy type 2A [1,4]. The enzyme is activated by autoproteolytic cleavage of insertion sequence 1 (IS1), which allows substrates and inhibitors gain access to the active site [4]. Substrates include the protein itself [3,4] and connectin/titin [2,5]. Belongs in peptidase family C2.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Protein domains and families: PROSITE:PDOC00126 , PROSITE:PDOC50203
Structural data: CSA , EC2PDB


  1. Sorimachi, H., Imajoh-Ohmi, S., Emori, Y., Kawasaki, H., Ohno, S., Minami, Y. and Suzuki, K.
    Molecular cloning of a novel mammalian calcium-dependent protease distinct from both m- and μ-types. Specific expression of the mRNA in skeletal muscle.
    J. Biol. Chem. 264: 20106-20111 (1989). [PMID: 2555341]
  2. Sorimachi, H., Kinbara, K., Kimura, S., Takahashi, M., Ishiura, S., Sasagawa, N., Sorimachi, N., Shimada, H., Tagawa, K. and Maruyama, K.
    Muscle-specific calpain, p94, responsible for limb girdle muscular dystrophy type 2A, associates with connectin through IS2, a p94-specific sequence.
    J. Biol. Chem. 270: 31158-31162 (1995). [PMID: 8537379]
  3. Rey, M.A. and Davies, P.L.
    The protease core of the muscle-specific calpain, p94, undergoes Ca2+-dependent intramolecular autolysis.
    FEBS Lett. 532: 401-406 (2002). [PMID: 12482600]
  4. García Díaz, B.E., Gauthier, S. and Davies, P.L.
    Ca2+ dependency of calpain 3 (p94) activation.
    Biochemistry 45: 3714-3722 (2006). [PMID: 16533054]
  5. Ono, Y., Torii, F., Ojima, K., Doi, N., Yoshioka, K., Kawabata, Y., Labeit, D., Labeit, S., Suzuki, K., Abe, K., Maeda, T. and Sorimachi, H.
    Suppressed disassembly of autolyzing p94/CAPN3 by N2A connectin/titin in a genetic reporter system.
    J. Biol. Chem. 281: 18519-18531 (2006). [PMID: 16627476]

[EC created 2007]