millimolar-calpain (m-calpain)

Calpastatin (184-210), an acetylated synthetic peptide derived from human calpastatin, effectively inhibits the calcium-dependent cysteine proteases, calpain I (µ-calpain) and calpain II (m-calpain), which require micromolar and millimolar calcium concentrations, respectively. Unlike its action on calpains, this 27 amino acid peptide does not inhibit papain (a cysteine protease) or trypsin (a serine protease). Encoded by exon 1B of Ac-calpastatin (184-210), it aligns with a section of inhibitory domain 1, showcasing its specificity and inhibitory function towards calpain enzymes.