Characterization and purification of a Ca²⁺ ion-activated neutral proteinase inhibitor in rabbit skeletal muscle

Abstract

Summary. This paper describes the isolation, purification and properties of a specific inhibitor of calcium-activated neutral proteinase (CaANP) in rabbit skeletal muscle.The inhibitor was a thermo-acid-stable protein degraded by trypsin and chymotrypsin and seemed to contain two polypeptide chains with molecular weights of 70 000 and 13 000 daltons. Maximal inhibitory activity was obtained at neutral pH. High salt concentrations were needed to suppressinhibition.Inhibitor concentration had no effect on the optimal Ca ++ ion levels for CaANP. These experiments also show that enzyme inhibitor association was instantaneous and did not need any incubation.Introduction.

Meat Tenderization: Possible Causes and Mechanisms. A Review.

“…A specific calpain inhibitor called calpastatin has also been isolated from muscles of various animal species (Kopitar er al. 1978;Cottin et al 1981;Takahaski-Nakamura et al 1981;Ishiura et al 1982). Nevertheless, little information is so far available on their distribution in muscles of different contractile and metabolic types and on their behavior during meat conditioning.…”

Sensory quality of meat as affected by muscle biochemistry and modern technologies

“…However, as this system is still poorly characterized, its possible contribution to meat tenderization remains still an unsolved issue. A specific calpain inhibitor called calpastatin has been also isolated from muscle of various animal species (53). Since endogenous protein inhibitors may constitute a powerful regulatory system for muscle proteinases, interest in their identification and characterization has recently markedly increased.…”