The structures of shellfish glycogens. I. The properties of oyster glycogen extracted by various methods.

Abstract

Gel filtration profile and ultracentrifugation analysis showed that the molecular weight of the commercial glycogen or the glycogen extracted with trichloroacetic acid (TCA) from whole oyster tissue was smaller than that of the glycogen extracted with dimethyl sulfoxide (DMSO). The degradation extents of glycogens extracted with DMSO and TCA on pullulanase treatment were 6.3% and 10.8 and that of commercial glycogen was 24.8%. Gel filtration profile or paper chromatogram of the pullulanase digest of the glycogen extracted with DMSO (DMSO-glycogen) was similar to those of the glycogen extracted with TCA (TCA-glycogen) and commercial glycogen. These results suggested that TCA-glycogen or commercial glycogen was degraded to some extent during the extraction of glycogen and became more susceptible to pullulanase keeping fundamental structure of the glycogen naltered. Electron microscopic study showed that the particle size (diameter) of DMSO-glycogen ranged 20-180 nm while the particle size of TCA-glycogen or commercial glycogen ranged 10-130 or 10-40 nm, respectively.