Amylose and Amylopectin Hybrid Materials via Enzymatic Pathways

Summary: Oligo- and polysaccharides are important macromolecules in living systems, showing their multifunctional characteristics in the construction of cell walls, energy storage, cell recognition and their immune response. Saccharides as organic raw materials can open new perspectives on the way to new biocompatible and biodegradable products which could help to overcome the problems resulting from the upcoming restrictions of petrochemical resources. Construction of well-defined carbohydrate polymer backbones is very challenging as it is difficult to realize complete regio and stereo-control of the glycosylating process. Most synthetic approaches are therefore based on the modification or degradation of naturally occurring polysaccharides resulting in less then perfect products. Enzymes have several remarkable catalytic properties compared with other types of catalysts in terms of their selectivity, high catalytic activity, lack of undesirable side reactions and operation under mild conditions. A biocatalytic pathway to synthesize saccharides is therefore very attractive as it results in well-defined polysaccharides avoiding the above drawbacks. When biogenic polysaccharides are combined with synthetic macromolecules, surfaces etc. materials with new interesting properties arise and the processability of the designed hybrid materials is facilitated. Amylose and amylopectin hybrid materials can be synthesized via enzymatic polymerization routes utilizing transferases. This approach opens access to well-defined hybrid structures bearing amylase or amylopectin moieties that cannot be synthesized by any other means.