Probe sialidase substrate specificity using chemoenzymatically synthesized sialosides containing C9-modified sialic acid

A library of alpha 2-3- and alpha 2-6-linked sialyl galactosides containing C9-modified sialic acids was synthesized from C6-modified mannose derivatives using an efficient one-pot three-enzyme system. These sialosides were used in a high-throughput sialidase substrate specificity assay to elucidate the importance of C9-OH in sialidase recognition.