Role of muscle endopeptidases and their inhibitors in meat tenderness

Heat Stabilization of the Tissue Proteome: A New Technology for Improved Proteomics

“…For example, the enkephalin neuropeptides (met-enk-RF and met-enk-RSL) were clearly detected in the stabilized samples and almost undetectable in the snap-frozen samples. Interestingly, the isotopically labeled neuropeptides added as internal standards were only detected in stabilized tissue, aside from the labeled protein fragment stathmin (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) which was detected independent of sample treatment, indicating ex vivo proteolytic activity and the relative stability of the stathmin (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) fragment.…”

“…Mice in a fourth sample group (n ) 4) were killed by focused microwave irradiation (1.4 s at 4.5-5 kW, Muromachi Kikai, Tokyo, Japan) which denature the proteins before dissection and homogenization. A microtip ultrasonicator (Vibra-Cell, Sonics & Materials) was used to homogenize the tissue in 5× the sample weight of 0.25% HAc extraction solution containing 40 mM of isotopically labeled stathmin (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), met-enkephalin, neurotensin, substance P (1-11), and substance P (1-7) as internal standards. The crude extract was centrifuged at 20 000g for 30 min at 4°C to pellet cell debris and ultrafiltered using a 10 kDa centrifugal cutoff filter (Microcon YM-10, Millipore) to isolate the peptide content.…”

Effects of a High-Pressure Treatment on the Activity and Structure of Rabbit Muscle Proteasome

“…In particular, cathepsin and calpain have been assumed to participate in proteolysis during meat aging. [20][21][22] Several studies have been made on the effects of high hydrostatic pressurization to treat intramuscular proteinase. Homma et al have reported that the pressureinduced increase in proteolytic level in the muscle was due to a release of cathepsins from lysosomes.…”

Influence of ultrasound and proteolytic enzyme inhibitors on muscle degradation, tenderness, and cooking loss of hens during aging

“…The rate of muscle degradation and post mortem tenderisation are highly dependent on the endog- Data are representatives of four independent experiments and are presented as means ± SD; different small and capital superscipts in the same row mean different significantly at P < 0.05 and P < 0.01 levels, respectively *P < 0.05 and **P < 0.01 means between different treatment groups are significant Values are expressed as absorbance (arbitrary units) per μg/ul protein concentration; each value represents the mean ± SD a-d means within a row with different superscripts are significantly different(P < 0.05) *P < 0.05 and **P < 0.01 means between different treatment groups are significant (Sentandreu et al 2002), a specific inhibitor, little is known about the potential endogenous inhibitors of the other proteolytic enzymes in animal skeletal muscle. The application of Protease Inhibitor Cocktails, AEBS, Aprotinin, Bestatin, E-64, Leupeptin, Pepstatin A, and Calpain inhibitor 1 on buffalo meat has suggested that higher calpain activities are responsible for the increased tenderness of water buffalo meat compared to beef soon after slaughter (Neath et al 2007).…”