抄録
The size and the shape of shellfish glycogen varied with the extraction procedure. The particles of glycogen prepared by extraction with dimethyl sulfoxide (DMSO) were relatively large (20-180nm, diam.) and showed rosette-like structure. The particles of glycogen prepared by trichloroacetic acid (TCA) extraction and the commercial glycogen were much smaller in size (10-130nm and 10-40nm, respectively) and did not show rosette-like structure. The general properties of these glycogen preparations were not significantly different from each other, except that the latter two preparations were more susceptible to pullulanase.
The size of the glycogen particles was decreased by treatment with TCA, phosphotungstic acid or 30% potassium hydroxide, but was not changed by treatment with 0.1M or 0.5M sodium hydroxide. Treatment with 2-mercaptoethanol did not disrupt large glycogen particles. Protease and β-amylase did not affect the size of glycogen particles. Large glycogen particles were partially split by treatment with α-amylase, suggesting that a large glycogen particle is composed of fundamental particles (20-30nm, diam.) linked through α-1, 4-glucan chains. On the basis of the foregoing results, a model of glycogen particle was proposed. The relation of the biosynthesis mechanism and the particle formation of glycogen was also discussed mainly from the viewpoint of the role of branching enzyme.
