Glycogen fine structure

Figure 10. Fine structure of liver glycogen as revealed by selective enzymatic gradation (110). O, , and Q represent glucose residues removed by first, second, and third treatment with muscle phosphorylase represents glucose units removed by amylo-(l - 6) glucosi-dase (the numbers beside these units indicate the number of treatment following phosphoryl-ase action).

In general, little information on the absorption spectra of iodine complexes of glycogens of known molecular structure is available, and attempts to relate spectra with details of fine structure appear to be premature. 

The action patterns of the above enzymes were determined by using the starch components as substrates with certain reservations, these enzymes may be used for studying the fine structure of glycogen. 

NSG binds to many kinds of protein, such as glycogen synthase and glycogen phos-phorylase, and contains minor constituents such as glucosamine and a phosphate group [6]. Furthermore, the fine structural properties of NSG can be influenced by the extraction method [20,21]. We can prepare ESG with high purity and controlled structure. While the major role of glycogen in vivo is to store glucose, other functions... 

Although, on the basis of chemical studies, it was possible to ascertain the gross structures of the molecules of starch and glycogen, the use of highly purified enzymes has become established as one of the most versatile and definitive methods for the determination of the fine structure of these polysaccharides. The use of these techniques in the examination of the fine structures of glycogen, amylopectin, and amylose will now be discussed. 

In view of the resistance of glycogen and its beta-limit dextrin to hydrolysis by R-enzyme," the fine structure of glycogen could not be investigated in a similar way. However, an attempt to show that this polysaccharide also fits the Meyer model was made by Cori and coworkers by using the enzymes phosphorylase and amylo-(l->6)-... 

Affinity Chromatography. The interaction of concanavalin A with alpha-D-glucans has been used in the determination of the fine structure of amylopectin and glycogen(88), where correlation between the external chain length of the glucan and the hydrodynamic volume has been established. 

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