Intermuscular variation in tenderness: association with the ubiquitous and muscle-specific calpains.

Abstract

The biochemistry of intermuscular variation in tenderness is not fully understood. To investigate the role of the calpains in this process we performed two experiments using bovine and ovine species. In the bovine experiment, two distinct muscles, longissimus thoracis et lumborum (LT) and psoas major (PM), were used. In the ovine experiment, four muscles, LT, PM, semimembranosus (SM), and semitendinosus (ST), were used. Muscles were sampled at death for the determination of the steady-state mRNA level of calpains and calpastatin and the activities of calpain 1, 2, and calpastatin. Muscles were also sampled to determine the temporal changes in pH, tenderness, and the activity of the ubiquitous calpain system during postmortem aging. The results of the relative rate of tenderization in both species was found to be related to muscle type; LT had the highest value in both species. Within species, the mRNA steady-state levels of calpain 1 and calpastatin were similar in various bovine and ovine muscles. Bovine calpain 2 mRNA level was significantly lower in the LT than in the PM. Ovine calpain 2 mRNA level was lower, but not significantly different, in the LT compared to the other muscles. The mRNA level of bovine calpain 3 was significantly higher in the LT muscle than in the PM. In the ovine, the mRNA level of calpain 3 was highest in the LT, followed by SM, PM, and ST. Results on the activity of the ubiquitous calpain system in various muscles at death were dependent on muscle type and species. Temporal changes in the activity of calpains and calpastatin during the first 24 h of postmortem aging were similar in the muscles studied: calpain 1 and calpastatin declined significantly and calpain 2 remained relatively unchanged. The temporal changes in muscle pH in both experiments indicated that the extent and rate of pH decline during aging was related to muscle type. Correlation analysis between the relative rate of tenderization and mRNA expression of calpains revealed a strong relationship with calpain 3 in both species.

Meat tenderness and muscle growth: is there any relationship?

“…The calpain proteolytic system consists of a ubiquitous system (m-calpain, m-calpain and calpastatin) and a tissue-specific calpain, which has been referred to as p94, calpain 3, or nCL-1 (Suzuki, Sorimachi, Yoshizawa, Kinbara, & Ishiura, 1995). In spite of some recent publications (Ilian, Bekhit, & Bickerstaffe, 2001;Ilian, Morton, et al, 2001) we have not discussed or assigned a role for calpain 3 in either muscle growth or meat tenderness. The bases for our decisions are described below.…”

“…Hence there is no information with regard to its structure, function, or proteolytic activity. Second, the publications that have assigned a role for calpain 3 in meat tenderization/ tenderness have either used mRNA abundance or have used an antibody generated against a protein based on calpain 3 mRNA sequence (Ilian, Bekhit, & Bickerstaff, 2001;Ilian, Morton, et al, 2001;Parr et al, 1999). These antibodies react with a polypeptide with molecular mass of 94 kDa.…”

Expression profiles of myostatin and calpastatin genes and analysis of shear force and intramuscular fat content of yak longissimus muscle

“…However, because meat tenderness is a complex trait and is affected by many factors (Purslow, 2005), it is difficult to be conclusive about the CAST function in tenderization of yak meat based on the present experimental data. The shear force and pH values of yak longissimus muscle obtained in this experiment are in the normal range of bovine muscle (Ilian et al, 2001;Torrescano et al, 2003). A similar extent of longissimus muscle pH decline among yak calves, adult yaks and cattle after aging indicates similar at-death levels of muscle glycogen.…”

Microarray Analysis on the Differences of Gene Expression in Longissimus Dorsi Muscle Tissue Between 1 and 24 Months Chinese Red Steppes

“…tenderization and mRNA expression of calpains revealed Intramuscular fat content (IMF) was correlated a strong relationship with calpain 3 in both species, with meat quality trails and showed significant effects bovine and ovine [r (bovine) = 0.522, r (ovine) = 0.706] on three aspects of meat: tenderness, flavor and juicy (Ilian et al, 2001). In contrast, Parr et al (1999) did not (De Vol et al, 1988).…”