Changes in the Calpain-Calpastatin and Cathepsin (B, B+l, H and D) During Postmortem Storage of Goat Muscles

Abstract

The objective of this study was to elucidate a relationship between some endogenous proteinases and their inhibitors in four different goat muscles during postmortem storage. Samples were taken from the longissimus dorsi (LD), biceps femoris (BF), semimembranosus (SM) and semitendinosus (ST) muscles stored up to 20 days postmortem at 5C. Activities of calpain‐I, calpain‐II, calpastatin, cathepsins (B, B+L, H and D) and cystatin(s) were determined. Decreases in calpain‐I and calpastatin activities were significantly more than that of calpain‐II activity. The cathepsin B, B+L, H and cystatin level were found to fall by 9–35 % after 20 days, whereas the cathepsin D showed 11–17% decline in all the muscles. Thus changes in muscle proteinases and their inhibitors during postmortem storage differ and the results may shed light on their role in myofibrillar proteolysis and goat meat tenderization.

Postmortem Changes in Myofibrillar Proteins of Goat Skeletal Muscles

“…However, fragmentation of myofibrils at the I–Z junction in the present study appears to be due to a weakness at the junction of the I‐band and Z‐disk and is independent of Z‐disk degradation. This variation in degradation might be due to the patterns of variation in enzyme activity and cytoskeletal proteolysis in muscles as we observed in our earlier studies (Nagaraj et al. 2002).…”

“…The LD and BF muscles had shown rapid proteolytic degradation compared to the SM muscle. This may be because of variation in postmortem proteolysis in different muscle types as we observed before (Nagaraj et al. 2002).…”

“…Calpain may degrade titin and nebulin to some extent. This is concluded by proteolytic enzyme studies where calpain activity was more compared to cathepsins at any period during postmortem (Nagaraj et al. 2002).…”

Autophagy during beef aging

“…32,35,36 However, lysosomal permeabilization and cathepsin release is often an early event in cell response to oxidative stress, not only in the autophagic processes but also in the apoptotic cascade 37 directly, as cathepsins cleave and activate caspases or indirectly by triggering mitochondrial dysfunction and subsequent release of mitochondrial proteins. [37][38][39] The magnitude of oxidative stress determines the degree of lysosomal destabilization and consequently whether reparative autophagy, apoptosis, or necrosis will follow.…”

Effects of Muscle Proteases, Endogenous Protease Inhibitors and Myofibril Fragmentation on Postmortem Aging of Goat Meat

“…Calpain I, calpain II and calpastatin were prepared from 5 g of the LD, BF, SM and ST muscles up to 24 h postmortem according to the procedure using (diethylamino)ethyl (DEAE)–Sephacel chromatography as described by Wheeler and Koohmaraie (1991). Fractions 45–62 were assayed for calpain I, fractions 75–95 for calpain II and fractions 17–40 for calpastatin activities according to the method of Nagaraj et al . (2002).…”