Properties of Viral Sialidases

Calcium ion (often tightly bound) is necessary for the activity of many viral sialidases (for review, Drzeniek, 1972, 1973). Factors such as temperature optima may vary widely, even among variants of a particular strain (Golubev et aL, 1973). 

Many potent inhibitors of viral sialidase are known. These include free sialic acid and its analogs such as 2-deoxy-2,3-dehydrosialic acid, substrate analogs with bulky N-substituents on the sialic acid, or lactonized sialic acid derivatives, oxamic acids, certain heavy metals (Hg ), and polyanionic compounds (for review, Drzeniek, 1972). 2-Deoxy-2,3-dehydro-A/ -trifluoroacetylneuraminic acid can also act as a potent inhibitor of myxovirus growth in tissue culture (Palese et aL, 1974). Isoquinoline derivatives apparently do not, as once thought, inhibit, but rather interfere with the analysis for free sialic acid (Shinkai and Nishimura, 1972). 

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