Sialic acid recognition and hydrolysis are essential parts of cellular function and pathogen infectivity. Neuraminidases are enzymes that detach sialic acid from sialosides, and their inhibition is a prime target for viral infection treatment. The connectivity and type of sialic acid influence the recognition and hydrolysis activity of the many different neuraminidases. The common strategies to evaluate neuraminidase activity, recognition, and inhibition rely on extensive labeling and require a large amount of sialylated glycans. The above limitations make the effort of finding viral inhibitors extremely difficult. We used synthetic sialylated glycans and developed a label-free electrochemical method to show that sialoside structural features lead to selective neuraminidase biosensing. We compared Neu5Ac to Neu5Gc sialosides to evaluate the organism-dependent neuraminidase selectivity-sensitivity relationship. We demonstrated that the type of surface and the glycan monolayer density direct the response to either binding or enzymatic activity. We proved that while the hydrophobic glassy carbon surface increases the interaction with the enzyme hydrophobic interface, the negatively charged interface of the lipoic acid monolayer on gold repels the protein and enables biocatalysis. We showed that the sialoside monolayers can serve as tools to evaluate the inhibition of neuraminidases both by biocatalysis and molecular recognition.
Bibliographical noteFunding Information:
M.H. and S.Y. are supported by COST Action 18103 INNOGLY and received funding from the European Innovation Council (EIC) under the European Union’s Horizon Europe research and innovation program (no. 101046369). R.K. gratefully acknowledges the financial support from the IISER, Pune, DBT, grants nos. BT/PR34475/MED/15/210/2020, STARS/APR2019/CS/426/FS/, and SERB/F/9228/2019–2020.
I.A. and A.S. are supported by the Hebrew University Center for Nanoscience and Nanotechnology Ph.D. Scholarship. S.Y. is the Benjamin H. Birstein Chair in Chemistry. The authors would like to thank V. Gutkin for XPS analysis.
© 2023 The Authors. Published by American Chemical Society.