Glycobiology World Congress

Biography

Biography: Rune Thorbjørn Nordvang

Abstract

In this study, sequence analysis and 3D alignment were used for the identification of a novel trans-sialidase, namely the trans-sialidase of Haemophilus parasuis. The H. parasuis trans-sialidase was one of four candidate enzymes selected from a database of 2909 protein sequences. It is the first time that a sequence analysis approach has been successful in identifying a trans-sialidase and additionally all remaining candidates (the sialidases of Pasteurella multosida, Actinomyces Oris and Manheimia Haemolytica) exhibited trans-activity, however they were ultimately not defined as trans-sialidases due to the comprehensive definition of a trans-silalidase. A trans-sialidase can be defined as a sialidase which, under a specific set of conditions, prefers the transfer of a sialic acid residue from a donor to an acceptor molecule over the hydrolysis of the donor. Trans-sialidases are sought after because they can be applied for the enzymatic production of human milk oligosaccharides (for addition to infant formula) from dairy side-stream products. So far, the only native trans-sialidase that has been found is the trans-sialidase of the human pathogen Trypanosomas cruzi. However, an additional trans-sialidase has been engineered through directed evolution of the sialidase of Trypanosomas rangeli. Rational inspection of the 3D structure of these known trans-sialidases was the basis for this study, and it is hoped that attributes of the newly identified H. parasuis trans-sialidase can be the basis of further trans-sialidase discovery.