Effect of the Redox Potential on the Muscle Enzyme System

Abstract

7his work presents the efect of redox potential in the range + 100 to -250 mV on the muscle cathepsins B, Hand L, lysosomal acid lipase and acid esterase and on neutral and basic lipases and neutral esterase from adipose tissue. Cathepsins B, Hand L need reducing conditions (below -50 mV) for maximal activity. Lysosomal acid lipase remains unaffected while activity of muscle acid esterase decreases sharply below -175 mV. Ihe activity of basic lipase from adipose tissue is also reduced below -80 mV while neutral lipase remains una..ected. The activity of neutral esterase is drastically reduced to negligible values below -1Ix) mK

Purification and Characterization of Cathepsin B from Ordinary Muscle of Mackerel (Scomber australasicus)

“…In general, the redox potentials of the postmortem muscle decreased from initial values of around +100 mV to -100 or even -200 mV (Ahn and Maurer, 1989). The activities of cathepsins B and L significantly increased when the redox potential was below -50 mM (Motilva et al, 1993). On the other hand, the level of cathepsin B of the postmortem muscle was also critical to the degradation of myofibrillar proteins by this proteinase.…”

“…According to the study on cathepsins B, D, and L and calpains in electrically stimulated chicken muscle (Etherington et al, 1990), the activity of calpains decreased markedly, but the activity of cathepsins B and L did not decrease after 48 h of storage at 15 °C. Considering the optimal pH (Figure 5), pH stability (Figure 6), and thermal stability (Table 3) of the purified cathepsin B, the redox potential (Motilva et al, 1993), and proteinase levels (Etherington et al, 1990), the purified cathepsin B and the previously purified cathepsin L (Lee et al, 1993) might play important roles in the postmortem autolysis of mackerel.…”

Salado y descongelado simultáneo en salmuera para la obtención de jamón curado de cerdo de raza ibérica.

“…El inicio en los cambios de los lípidos del jamón ibérico ocurre en las primeras etapas del proceso de elaboración, el salado y el postsalado (Pezzani et al, 1998), desarrollándose la mayor parte de la lipólisis en los primeros 5 meses del proceso (Motilva et al, 1993b;1993c), siendo responsables los sistemas enzimáticos del músculo, del desarrollo de los ácidos grasos libres.…”