Protein engineering study of β-mannosidase to set up a potential chemically efficient biocatalyst.

This study is focused on the analysis and mutagenesis of β-mannosidase from Bacteroides thetaiotaomicron with the aim of broadening its substrate specificity to 2-acetamido-2-deoxy-β-d-mannopyranosyl (β-ManNAc) derivatives. Various conformations ((4)C1, (4)H5 and (1)S5) of native and modified ligands were docked to the binding site of the protein to determine the most suitable conformation of sugars for further hydrolysis. Key amino acid residues were mutated in silico focusing on stabilizing the acetamido group of β-ManNAc as well as forming the oxazoline intermediate needed for hydrolysis.