Keiko Hata

Purification and properties of glycogen phosphorylase from the adductor muscle of the scallop, Patinopecten yessoensis

Abstract 1. 1. Glycogen phosphorylase from the adductor muscle of scallop was purified. 2. 2. The mol. wts of the purified phosphorylase and its subunit were 245,000 and 120,000 respectively. 3. 3. This enzyme was most active at pH 6.8 and 30°C. This enzyme activity was inhibited by glucose, glucose-6-P, fructose-6-P, ATP, ADP, UDPG, HgCl2, CuCl2 and SDS, and activated by AMP. 4. 4. The K a value of this enzyme for AMP was 17.4 μM. The K m values of this enzyme for glucose-1-P and glycogen were 2.2 mM and 3.0 mM, respectively. 5. 5. It appears that physiological glucogenolysis in scallop adductor is regulated by the change of phosphorylase activity dependent on the concentration of glucose-6-P, AMP and ATP.

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 Hg2+, Cu2+, Zn2+, SDS and G6P. 5. 5. The Km of phosphorylase b for AMP was 253 μM. The Km of phosphorylases a and b for GIP and glycogen were 2.8, 0.61 mM and 3.2, 1.0 mM, respectively.

S11.6 Purification and characterization of gangliosidehydrolyzing sialidase from bovine brain

Subsequently we could determine the structures of three Chol1/3 gangliosides to be GDlaa , G T l b a and G M l a by using a2-3 linkage specific sialidase (kindly supplied by Dr. Yu-Teh Li). They possessed N-acetylneuraminic acid attached to N-acetylgalactosamine in a2-6 linkage. From the result of immunohistochemical staining of rat brain with monoclonal antibody, GGR41 [3], recognizing Cholla gangliosides, it was demonstrated that they were stained intensely the neuropile of dorsal horn on spinal cord, being presumably expressed on the cholinergic nerve terminals. This staining pattern, which is different from that with anti-Chol-1, suggests that Chol la gangliosides are expressed on the different region from Chol-lfl gangliosides in the cholinergic neuron. (1) Richardson, P. J. et al. (1982) J. Neurochem., 38, 1605 1614. (2) Hirabayashi, Y. et aL (1992) J. Biol. Chem., 267, 1297312978. (3)Kusunoki, S. et al. submitted for publication.