Acetylation of Actin K328 Contributes to a Loss in Tropomyosin-Mediated Inhibition of Myosin Binding

Effects of acetylation on dissociation and phosphorylation of actomyosin in postmortem ovine muscle during incubation at 4 °C in vitro

This study aimed to assess the effects of acetylation levels on actomyosin disassociation and phosphorylation of lamb during incubation at 4 °C. Samples of whole proteins from lamb longissimus thoracis muscles were prepared and assigned into three treatments (high, middle and low acetylation groups). The results showed that deacetylation of myosin heavy chain and actin was inhibited by lysine deacetylase inhibitor trichostatin A and nicotinamide in this study. Phosphorylation levels of myosin heavy chain and actin were inhibited by their acetylation during incubation in vitro. Actomyosin disassociation degree in high acetylation group was significantly lower than that in middle and low acetylation groups (P < 0.05). The ATPase activity in high acetylation group was significantly higher than that in middle and low acetylation groups (P < 0.05). In conclusion, acetylation of myosin heavy chain and actin inhibited actomyosin dissociation by inhibiting their phosphorylation at 4 °C in vitro.