Liha töötlemine
1955) and Calpains are Ca2+-dependent cysteine prote-
in phagocyte cells but have also been found ases with optimal activity at neutral pH and
in the sarcoplasmic reticulum of muscle are found in all kinds of living organisms,
cells (Allen and Goll 2003). Ultrastructural including animals, plants, fungi, and bacteria.
studies indicate lysosomes are prevalent in Discovered about a decade after cathepsins
fetal muscle tissue but occur much less fre- (Guroff 1964), calpains have been exten-
quently in adult skeletal muscle. Cathepsins sively researched and the subject of many
are distinguished by their active sites (aspar- reviews on muscle proteolysis (Goll et al.
tic, cysteine, and serine proteases) and 1992, 1998, 2003; Geesink et al. 2000; Ilian
substrate specificity. Over 15 lysosomal et al. 2001; Friedrich and Bozóky 2005;
cathepsins have been identified, but only Geesink et al. 2005; Koohmaraie and Geesink
annaabi.ee 
