The calpain system in three muscles of normal and callipyge sheep.

Abstract

Activities of mu- and m-calpain and of calpastatin were measured at four different times during postmortem storage (0, 1, 3, and 10 d) in three muscles from either callipyge or noncallipyge (normal) sheep. The weights of two muscles, the biceps femoris and the longissimus, are greater in the callipyge phenotype, whereas the weight of the infraspinatus is not affected. The activity of m-calpain was greater (P < 0.05) in the biceps femoris and longissimus from callipyge than in those from normal sheep, but it was the same in the infraspinatus in the two phenotypes. The extractable activity of m-calpain did not change (biceps femoris and infraspinatus) or decreased slightly (longissimus) during postmortem storage. Extractable activity of mu-calpain decreased to zero or nearly zero after 10 d postmortem in all muscles from both groups of sheep. The rate of decrease in mu-calpain activity was the same in muscles from the callipyge and normal sheep. At all time points during postmortem storage, calpastatin activity was greater (P < 0.05) in the biceps femoris and longissimus from the callipyge than from the normal sheep, but it was the same in the infraspinatus from callipyge and normal sheep. Calpastatin activity decreased (P < 0.05) in all three muscles from both phenotypes during postmortem storage; the rate of this decrease in the callipyge biceps femoris and longissimus and in the infraspinatus from both the callipyge and normal sheep was slow, especially after the first 24 h postmortem, whereas calpastatin activity in the biceps femoris and longissimus from the normal sheep decreased rapidly. During postmortem storage, the 125-kDa calpastatin polypeptide was degraded, but the 80-kDa subunit of mu-calpain was cleaved only to 76- and 78-kDa polypeptides even though extractable mu-calpain activity declined nearly to zero. Approximately 50 to 60% of total mu-calpain became associated with the nonextractable pellet after 1 d postmortem. The myofibril fragmentation index for the biceps femoris and longissimus from normal sheep increased significantly during postmortem storage. The fragmentation index for the infraspinatus from the callipyge and normal sheep increased to an intermediate extent, whereas the index for the biceps femoris and longissimus from the callipyge did not change during 10-d postmortem storage. The results suggest that postmortem tenderization is related to the rate of calpastatin degradation in postmortem muscle and that calpastatin inhibition of the calpains in postmortem muscle is modulated in some as yet unknown manner.

Assessment of calpain and caspase systems activities during ageing of two bovine muscles by degradation patterns of αII spectrin and PARP‐1

“…In this study, no correlation between SBDP150 level and caspase activity was found, suggesting that the increasing of SBDP150 during ageing could be mainly due to calpain rather than caspase activity. Also Delgado et al (2001) detected calpain-1 activity till 72 h post mortem in skeletal muscles of lamb.…”

Effects of breed, muscle type, and frozen storage on physico-chemical characteristics of lamb meat and its relationship with tenderness

“…The myofibrillar fragmentation index (MFI) was determined using the method described by Hopkins, Littlefield, and Thompson (2000) and Delgado, Geesink, Marchello, Goll, and Koohmaraie (2002). Duplicate 2 g samples were homogenized for 30 s with a 10 s break in 20 mL of ice-cold buffer.…”

The influence of selected genes on sheep performance traits

“…Jak donosi Palmer, et al (1998) gen ten pełni znaczącą rolę w formowaniu i rozpadzie mięśni. Kalpastatyna, hamując działanie kalpain, ma wpływ na proces kruszenia i dojrzewania mięsa (Delgado, et al, 2001). W literaturze opisano przypadki polimorfizmów genu kodującego kalpastatynę, które mogą wpływać na cechy użytkowości mięsnej owiec.…”