Identification of a Novel Fungal α- l -Fucosidase with Transfucosylation Potential

Abstract

Fucosylated carbohydrates are a vital part of human nutrition. They act as prebiotics, nourishing beneficial gut bacteria and helping shape the gut microbiome. Enzymatic synthesis is a convenient method to access these molecules. Fungal α-l-fucosidases are glycoside hydrolases that naturally cleave terminal α-linked fucose residues from glycans; those with synthetic capabilities are conveniently applicable in glycoengineering. This study investigates the fucosylation potential and regioselectivity of rare GH29 α-l-fucosidases from filamentous fungi. The screening of production of putative α-l-fucosidases by fungal strains using various inducers was combined with in silico analysis. Recombinant α-l-fucosidases were produced on a large scale and characterized with respect to their substrate specificities and pH optima. A novel transfucosylating α-l-fucosidase from Aspergillus phoenicis was thus identified and characterized. It was capable of regioselective formation of an α-(1 → 2)-linked fucosylated product. These findings highlight the potential of selected fungal α-l-fucosidases as promising tools for glycoengineering of fucosylated carbohydrates.