This project will use competence and technology established during three decades of research to explore the basic mechanisms underlying the processivity and specificity of a family of enzymes called mannuronan C-5 epimerases acting on the polysaccharide alginate. Alginates are linear, nonrandom copolymers of mannuronic acid (M) and its C-5 epimer guluronic acid (G). Alginate is synthesised as poly-mannuronan which is then converted into alginate by the epimerase enzymes. The hypothesis is that the plethora of non-random structures found in alginate is a consequence of epimerases with different degrees of processivity. The mode of action of these enzymes will be elucidated through combining computational enzyme design with advance experimental approach including three-dimensional (3D) structure determination, characterisation of enzyme activities, and determination of single molecular interactions between the enzymes and substrates with precisely defined structure and composition. The epimerases represent a unique model for understanding other enzymes involved in biosynthesis of polysaccharides with non-random block structures, e.g. heparin and heparan sulphate. The consortium includes Dep. of Biotechnology and Dep. of Chemistry at the Norwegian University of Science and Technology and SINTEF Materials and Chemistry. The partners hold extensive experience in biopolymer synthesis, modification and characterization, computational chemistry, production and utilization, biomolecule interaction studies, and overall protein structure determination. Furthermore, the consortium will seek active collaboration with their international partners, especially Roscoff Marine Station, University of Amsterdam and Umeå University. Together, this knowledge base combined with the partners state-of-the art infrastructure and research network renders the consortium well-suited to accomplish the challenging objectives set forth in the proposal.
