Gel permeation chromatography of polysaccharides: Universal calibration curve.

Sullivan

2014

Aust. J. Chem.

Glycogen is a highly branched polymer of glucose, functioning as a blood-glucose buffer. It comprises relatively small b-particles, which may be joined as larger aggregate a-particles. The size distributions from size-exclusion chromatography (SEC, also known as GPC) of liver glycogen from non-diabetic and diabetic mice show that diabetic mice have impaired a-particle formation, shedding new light on diabetes. SEC data also suggest the type of bonding holding b-particles together in a-particles. SEC characterisation of liver glycogen at various time points in a day/night cycle indicates that liver glycogen is initially synthesised as b-particles, and then joined by an unknown process to form a-particles. These a-particles are more resistant to degradation, presumably because of their lower surface area-to-volume ratio. These findings have important implications for new drug targets for diabetes management.

Section: Glycogen Size Characterisationmentioning

confidence: 81%

The Molecular Size Distribution of Glycogen and its Relevance to Diabetes

Sullivan

2014

Aust. J. Chem.

“…For SEC, V h is proportional to the product of the weight-average intrinsic viscosity and the number-average molecular weight [26][27][28][29] of a given sample:…”

Section: Techniques and Assumptionsmentioning

confidence: 99%

Characterization Methods for Starch-Based Materials: State of the Art and Perspectives

Witt

2013

Aust. J. Chem.

Improving starch-containing materials, whether food, animal feed, high-tech biomaterials, or engineering plastics, is best done by understanding how biosynthetic processes and any subsequent processing control starch structure, and how this structure controls functional properties. Starch structural characterization is central to this. This review examines how information on the three basic levels of the complex multi-scale structure of starch -individual chains, the branching structure of isolated molecules, and the way these molecules form various crystalline and amorphous arrangements -can be obtained from experiment. The techniques include fluorophore-assisted carbohydrate electrophoresis, multipledetector size-exclusion chromatography, and various scattering techniques (light, X-ray, and neutron). Some examples are also given to show how these data provide mechanistic insight into how biosynthetic processes control the structure and how the various structural levels control functional properties.

“…That separation in SEC depends only on V h and not on any structural parameters has been postulated based on limited experimental data for branched polymers (including starch) [19,20,51]. This widely adopted assumption merits further experimental checks for polysaccharides with a range of structures and solvents, as it may well not be valid for some (or even many) such analytes.…”

Section: Size Calibrationmentioning

confidence: 99%

Characterization of branched polysaccharides using multiple‐detection size separation techniques

Vilaplana

J of Separation Science

2010

234

151

The structure of branched polysaccharides involves a hierarchy of levels, from the constituent sugars, then the branching pattern, up to the macromolecular architecture, and then supramolecular organization. Finding causal relations between this complex structure/architecture and both (bio)synthetic mechanisms and final properties is needed for understanding the functionality of branched polysaccharides, which is important in fields ranging from improved nutrition and health through to papermaking and pharmaceuticals. The structural complexity makes this task especially challenging. This review focuses on the best current means to obtain reliable branch chain and size distributions using size-separation technologies coupled with number-, mass- and molecular-weight-sensitive detectors. Problems with current technologies are also critically appraised.