UDP-glucose: Glucan Synthetase in Developing Cotton Fibers: II. Structure of the Reaction Product.

The solubility properties, composition, and structure of the radioactive product synthesized from UDP-[(14)C]glucose by a highly active cotton fiber glucan synthetase have been determined. Product obtained under the following three different conditions was analyzed: at high and low substrate concentrations by detached fibers, and at high substrate concentrations with an isolated particulate preparation. The results of acetic and nitric acid digestion, enzyme digestion, total acid hydrolyses, periodate oxidation, partial acid hydrolyses, and methylation analyses all support the conclusion that the product of the glucan synthetase produced under all three assay conditions is a linear beta-(1-->3)-glucan.