The Properties and Solution Behaviour of Synthetic Glycogen with Long External-Chains†

Synthetic glycogen with long external chain-lengths has been prepared from glycogen and glucose-1-phosphate by the action of potato phosphorylase. Samples having external chains of average lengths of 9.7, 12.1, and 37.8 glucose units (original glycogen = 7.5 glucose units) have been prepared. The iodine-binding characteristics, the behaviour on β-amylolysis, and the dependence of sedimentation coefficient on concentration have been investigated. Results are consistent with the concept that the synthetic samples have a few exceedingly long external chains with the remainder the same length as in native glycogen. The significance of these results is discussed.