PURIFICATION AND PROPERTIES OF GLYCOGEN-PHOSPHORYLASE FROM THE ADDUCTOR MUSCLE OF THE OYSTER, CRASSOSTREA-GIGAS

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. Native and subunit molecular weights of these enzymes were 250,000 and 120,000, respectively. 3. Optimum pH and temperature were 6.8 and 30-degrees-C, respectively. 4. These enzymes were strongly inhibited by Hg2+, Cu2+, Zn2+, SDS and G6P. 5. The K(m) of phosphorylase b for AMP was 253 muM. The K(m) of phosphorylases a and b for G1P and glycogen were 2.8, 0.61 mM and 3.2, 1.0 mM, respectively.