α-1,4-glucosans-XVII. The molecular structure of some glycogens

Abstract

1. 1. Thirty-two samples of glycogen from thirteen different species of animals have been examined by periodate oxidation, enzymic degradation, iodine-staining and concanavalin-A reaction methods of analysis. The majority of the samples had average chain lengths of 12–15 glucose residues. 2. 2. Turbidity measurements on thirteen of the above samples indicated molecular weight values in the range 5 to 100 × 10 6. 3. 3. The ingestion of D-galactose by starved rabbits does not produce a liver glycogen with an abnormally low degree of branching. A similar result was obtained after the ingestion of sucrose by a starved pig. 4. 4. Lyo-(TCA-extractable, “free”) and desmo-(alkali-extractable, “fixed”) glycogens isolated from the livers of starved and fed rabbits have been similar chain lengths, indicating that liver glycogen is not chemically heterogeneous.