ENTRY       EC 3.4.22.17
NAME        Calpain
            Ca2+-activated neutral protease (CANP)
            mu-calpain
            calpain I
            muCANP
            m-calpain
            calpain II
            mCANP
CLASS       Hydrolases
            Acting on peptide bonds (peptidases)
            Cysteine endopeptidases
REACTION    Preferential cleavege: Tyr+, Met+, or Arg+ with Leu or Val as the
            P2 residue
SUBSTRATE   Protein
            Peptide
            Troponin I
            Tropomyosin
            C-Protein
            H2O
PRODUCT     Protein
            Peptide
COFACTOR    Calcium
COMMENT     An intracellular, non-lysosomal enzyme.  There are two main types
            of calpain: one with high Ca2+ sensitivity in the micromolar
            range, called mu-calpain, calpain I or muCANP, and the other with
            low Ca2+ sensitivity in the millimolar range, called m-calpain,
            calpain II or mCANP.  Forms of intermediate Ca2+ sensitivity also
            exist.  A component of lens neutral proteinase (formerly
            EC 3.4.24.5).
DISEASE     MIM: 114240  Calpain, large polypeptide L3; Muscular dystrophy,
                         limb-girdle, type 2A, 253600 (3)
MOTIF       PS: PS00018  D-x-[DNS]-{ILVFYW}-[DENSTG]-[DNQGHRK]-{GP}-[LIVMC]-
                         [DENQSTAGC]-x(2)-[DE]-[LIVMFYW]
            PS: PS00139  Q-x(3)-[GE]-x-C-[YW]-x(2)-[STAGC]-[STAGCV]
            PS: PS00639  [LIVMGSTAN]-x-H-[GSACE]-[LIVM]-x-[LIVMAT](2)-G-x-
                         [GSADNH]
            PS: PS00640  [FYCH]-[WI]-[LIVT]-x-[KRQAG]-N-[ST]-W-x(3)-[FYW]-G-
                         x(2)-G-[LFYW]-[LIVMFYG]-x-[LIVMF]
GENES       HSA: CANP) CAPN1(mu CAPN2(Hs.76288) CAPN3(LGMD2A) CAPN4(Hs.74451)
                 CAST(Hs.78220)
DBLINKS     University of Geneva ENZYME DATA BANK: 3.4.22.17
            WIT (What Is There) Metabolic Reconstruction: 3.4.22.17
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