Effects of different ATP contents on phosphorylation level of glycogen phosphorylase and its activity in lamb during incubation at 4 ℃ in vitro

Abstract

AbstractThe aim of this study was to investigate the effects of ATP on glycogen phosphorylase activity in lamb during incubation at 4℃ in vitro. Sarcoplasmic proteins from lamb were extracted and treated with different contents of ATP to get three groups of glycogen phosphorylase with low, middle and high ATP content groups, the amount of ATP were 0.5, 2.0 and 2.5 μM per 100 μg protein, respectively. The control group was without ATP adding. The results showed that ATP promoted the phosphorylation of glycogen phosphorylase, and phosphorylation modification promoted its activity. But ATP inhibited the activity of glycogen phosphorylase and ATP preferentially participated in phosphorylation. When ATP concentration was 0.5 μM per 100 μg protein, the effect of phosphorylation modification on the activity of glycogen phosphorylase was equal to the inhibition of ATP. The effect of glycogen phosphorylase phosphorylation on its activity gradually became dominant as incubation time prolonged.