Purification and characterization of cathepsin B from carp ordinary muscle.

Abstract

Cathepsin B [EC 3.4.22.1] was purified from carp Cyprinus carpio muscle by ammonium sulfate fractionation at pH 3.0, CM-cellulose chromatography, gel-filtration on Ultrogel AcA54, and

Effects of mackerel cathepsins L and L-like, and calpain on the degradation of mackerel surimi

“…Furthermore, carp cathepsin B activity increased in the presence of 0.1–0.5 M NaCl. 33 Consequently, cathepsins B, L and L‐like in surimi might not be affected by grinding with 2.5% NaCl. The loss of cathepsins B, L and L‐like activity (about 28%) ( Table 1) after grinding with 2.5 % NaCl was considered to be due to the denaturation of enzymes during grinding.…”

Hydrolytic Action of Salmon Cathepsins B and L to Muscle Structural Proteins in Respect of Muscle Softening.

“…This view was inferred from the fact that extensively high activities of cathepsins B, D and L were detected8-11) in such salmon muscle being very susceptible to softening, and concurrently, the presence of number of phagocytic cells were immunohistochemically revealed in and around the muscle fibers.21) The possibility of participation by cathepsin D in the extensive muscle softening was ruled out, because this enzyme in general cannot manifest its activity in the physiological pH region.22) Cathepsin B was suspected, and could not be excluded, because purified cathepsin B exhibited weak endopeptidase activity against protein substrates, except for dipeptidylcarboxypeptidase activity. 15,[23][24][25] Autolysis of the post-mortem muscle of domestic animals, poultry, and fish has been long considered to be proteolysis of the myofibril structure. 1,26,27) Recently, poteolysis of the macromolecular components of myofibril, particularly of connectin and nebulin which contribute to the elasticity of muscle, has become of interest concerning postmortem softening of muscle.27-30) Furthermore, connective tissue, consisting mainly of collagen, should not be ruled because it plays an important role in the physical properties of muscle tissue.…”

Mackerel Cathepsins B and L Effects on Thermal Degradation of Surimi

“…According to Kinoshita et al (1992), the proteolytic activity of sarcoplasmic-50ЊC-MIP (modori-inducing proteinases) from threadfin bream against actomyosin was not affected by addition of 10% NaCl. Furthermore, carp cathepsin B activity increased in the presence of 0.1ϳ0.5 M NaCl (Hara et al, 1988). Consequently, cathepsins B and L in surimi might not be affected by grinding with 2.5% NaCl.…”