Bioengineering and application of novel glucose polymers

Glucan phosphorylase, branching enzyme, and 4- alpha -glucanotransferase were employed to produce glucose polymers with controlled molecular size and structures. Linear or branched glucan was produced from glucose-1-phosphate by glucan phosphorylase alone or together with branching enzyme, where the molecular weight of linear glucan was strictly controlled by the glucose-1- phosphate/primer molar ratio, and the branching pattern by the relative branching enzyme/glucan phosphorylase activity ratio. Cyclic glucans were produced by the cyclization reaction of 4- alpha -glucanotransferases and branching enzyme on amylose and amylopectin. Molecular size and structure of cyclic glucan was controlled by the type of enzyme and substrate chosen and by the reaction conditions. This in vitro approach can be used to manufacture novel glucose polymers with applicable value.