Purification and properties of glycogen phosphorylase from the adductor muscle of the oyster, Crassostrea gigas

Abstract

1. 1. Glycogen phosphorylases a and b from the adductor muscle of oyster were purified. Specific activities of glycogen phosphorylase a and b were 30 U/mg protein and 16 U/mg protein respectively. 2. 2. Native and subunit molecular weights of these enzymes were 250,000 and 120,000, respectively. 3. 3. Optimum pH and temperature were 6.8 and 30°C, respectively. 4. 4. These enzymes were strongly inhibited by Hg 2+, Cu 2+, Zn 2+, SDS and G6P. 5. 5. The K m of phosphorylase b for AMP was 253 μM. The K m of phosphorylases a and b for GIP and glycogen were 2.8, 0.61 mM and 3.2, 1.0 mM, respectively.