Purification of cathepsin D from rabbit skeletal muscle and its action towards myofibrils

Skeletal Muscle Proteases and Protein Turnover

“…Okitani et al (1988) have recently developed a procedure for separating cathepsins Band L from skeletal muscle extracts, so the question of whether cathepsin B can degrade muscle proteins may soon be resolved. In agreement with Schwartz and Bird (1977), Okitani et al (1981a) found that cathepsin D degraded myosin heavy chain at pH 3 to 4. cDNAs for cathepsins B, D, H, and L have recently been cloned and sequenced (lshidoh et al, 1987(lshidoh et al, a,b: Faust et al, 1985. These studies show that all four of these proteases are synthesized in a form that contains a signal peptide of 17 to 21 amino acid residues and a pro-peptide region of 44 (cathepsin D) to 96 amino acid residues.…”

Cathepsin D—Many functions of one aspartic protease

“…General protein degradation and turnover Many (including ↓) [36] Activation and degradation of polypeptide hormones, FGF [37] chemokines, growth factors and their receptors Plasminogen [38] Prolactin [39,40] Endostatin [41] Osteocalcin [42] Thyroglobulin [43] Insulin [44] Glucagon [45] IL-1 [46] IGFBP [47] Androgen receptor [48] Parathyroid hormone [49] MIP-1 alpha [50] MIP-1 beta [50] SLC [50] Activation of enzymatic precursors Cathepsin B [51,52] Cathepsin L [51,53] Transglutaminase 1 [54] Brain antigen processing Amyloid beta A4 protein [55,56] Tau [57] Tubulin [58] Myelin basic protein [59] Mhtt [60] Apolipoprotein E [61] Alpha-synuclein [62] Degradation of cytoskeletal proteins Neurofilaments [63] Actin [64,65] Myosin [64,66] Tropomyosin [65] Monocyte-mediated fibrinolysis Fibrinogen [67,68] Fibrin [67,68] Regulation of apoptosis Bid [69] Thiredoxin-1 [70] Processing of enzyme activators and inhibitors Prosaposin …”

The effect of calcium activated protease (CAF) and cathepsin D on bovine muscle myofibrils under varying conditions of pH and temperature

“…It has also been reported that rabbit skeletal muscle cathepsin D degraded alpha-actinin (Okitani et al, 1981;Matsumoto et al, 1982); however, no similar effects on alpha-actinin were observed with cathepsin D in my study. Because their studies may have been done with impure enzymes, the effects ascribed to cathepsin D may have been due to other contaminating proteases.…”

“…The myofibrillar proteins myosin and actin are degraded by cathepsin H and it has been estimated that it is five times faster at degrading myosin than is cathepsin B . Cathepsin H is not inhibited by the peptide antipain and is only partially inhibited by leupeptin (Okitani et al, 1981).…”

“…The cathepsin D isolation (crude cathepsin D) from bovine cardiac muscle was performed as described by Barrett (1977) for the rat skeletal muscle enzyme and as outlined in Figure 36. Chromatographic procedures used were based on those described by Afting and Becker (1981) Okitani et al, 1981;Matsumoto et al, 1982).…”