Sialic acid
Viral neuraminidases are the members of the glycoside hydrolase family 34 CAZY GH_34 which comprises enzymes with only one known activity; sialidase or neuraminidase . Neuraminidases cleave the terminal sialic acid residues from carbohydrate chains in glycoproteins. Sialic acid is a negatively charged sugar associated with the protein and lipid portions of lipoproteins.