title: Acid hydrolysis and molecular density of phytoglycogen and liver glycogen helps understand the bonding in glycogen α (composite) particles.
abstract: Phytoglycogen (from certain mutant plants) and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired.
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia.
authors: Prudence O
authors: PO
authors: Powell
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia.
authors: Mitchell A
authors: MA
authors: Sullivan
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia.
authors: Joshua J
authors: JJ
authors: Sheehy
authors: School of Chemistry and Molecular Biosciences, Faculty of Science, The University of Queensland, Brisbane, QLD, Australia.
authors: Benjamin L
authors: BL
authors: Schulz
authors: Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia.
authors: Frederick J
authors: FJ
authors: Warren
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia.
authors: Robert G
authors: RG
authors: Gilbert
mesh_terms: D000818:Animals; D003920:Diabetes Mellitus / Q000378:metabolism; D006003:Glycogen / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D006868:Hydrolysis; D008112:Liver Glycogen / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D051381:Rats; D013213:Starch / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry*
chemical_list: D008112:Liver Glycogen; D013213:Starch; D006003:Glycogen