Volume I. Glycogen: A historical overview, an adjunct to thesis. Volume II. Non-glucose components of glycogen

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7152140

Kirkman, B R

Investigations have been carried out on three non-glucose components of native glycogen: protein, glucosamine, and phosphate. The protein, glycogenin, appears to serve as the primer upon which new molecules of glycogen are synthesized. When cell extracts are incubated with ({sup 14}C)UDPG, ({sup 14}C)glucose becomes transferred onto pre-existing chains of alpha-1,4 linked glucose associated with free glycogenin. The transferase and glycogenin remain associated during various purification steps. Liver glycogen appears to contain less than 0.02% protein which may correspond to the presence of one molecule of glycogenin (37 kDa) per alpha particle of liver glycogen. The core beta particle within each alpha particle may be synthesized upon glycogenin, while the remaining 20-40 beta particles may arise from each other. The author has demonstrated the natural occurrence of glucosamine in liver glycogen (but not muscle glycogen) from various species in an amount of about one molecule per molecule of glycogen. The glucosamine is underivatized, appears to be randomly scattered in the glycogen, and may be derived from dietary galactosamine. Similar to Fontana (1980), the author observed that native liver glycogen could be fractionated on DEAE-cellulose apparently on the basis of phosphate content. The more strongly bound glycogen possessed a greater molecular weight and content of glucosamine and phosphate. Possible explanations for these subfractions are considered. The phosphate appears to be concentrated near the center of the glycogen molecules. About 30% appears to be associated with glucose-6P and the remainder with an unidentified phosphodiester. The phosphate may stimulate glycogen synthesis. How the phosphate becomes incorporated is unknown.

• Research Organization: Miami Univ., FL (USA)
• OSTI ID: 7152140
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
BIOCHEMISTRY
BIOSYNTHESIS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CHEMISTRY
DATA
DIGESTIVE SYSTEM
EXPERIMENTAL DATA
GLANDS
GLUCOSAMINE
GLYCOGEN
HEXOSAMINES
HEXOSES
INFORMATION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER
MOLECULAR STRUCTURE
MONOSACCHARIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
POLYSACCHARIDES
PROTEINS
SACCHARIDES
SYNTHESIS
TRACER TECHNIQUES