title: Improving size-exclusion chromatography separation for glycogen.
abstract: Glycogen is a hyperbranched glucose polymer comprised of glycogen β particles, which can also form much larger composite α particles. The recent discovery using size-exclusion chromatography (SEC) that fewer, smaller, α particles are found in diabetic-mouse liver compared to healthy mice highlights the need to achieve greater accuracy in the size separation methods used to analyze α and β particles. While past studies have used dimethyl sulfoxide as the SEC eluent to analyze the molecular size and structure of native glycogen, an aqueous eluent has not been rigorously tested and compared with dimethyl sulfoxide. The conditions for SEC of pig-liver glycogen, phytoglycogen and oyster glycogen were optimized by comparing two different eluents, aqueous 50 mM NH₄NO₃/0.02% NaN₃ and dimethyl sulfoxide/0.5% LiBr, run through different column materials and pore sizes at various flow rates. The aqueous system gave distinct size separation of α- and β-particle peaks, allowing for a more detailed and quantitative analysis and comparison between liver glycogen samples. This greater resolution has also revealed key differences between the structure of liver glycogen and phytoglycogen.
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors: Mitchell A
authors: MA
authors: Sullivan
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors: Prudence O
authors: PO
authors: Powell
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors: Torsten
authors: T
authors: Witt
authors: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia; Division of Glycoscience, School of Biotechnology and Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91 Stockholm, Sweden.
authors: Francisco
authors: F
authors: Vilaplana
authors: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
authors: Eugeni
authors: E
authors: Roura
authors: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia. Electronic address: b.gilbert@uq.edu.au.
authors: Robert G
authors: RG
authors: Gilbert
mesh_terms: D000818:Animals; D002850:Chromatography, Gel / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D006003:Glycogen / Q000737:chemistry / Q000302:isolation & purification* / Q000648:ultrastructure; D012997:Solvents; D013552:Swine
chemical_list: D012997:Solvents; D006003:Glycogen; D004121:Dimethyl Sulfoxide
keywords: Glycogen; Improved resolution; Size-exclusion chromatography (SEC); Structural characterization