Neuraminidase activity of blue eye disease porcine rubulavirus: Specificity, affinity and inhibition studies

This work describes the purification and characterization of PorPV HN protein (isolate PAC1). The specificity of neuraminidase is restricted to sialyl(α2,3)lactose (3SL). HN showed typical Michaelis-Menten kinetics with fetuin as substrate (km = 0.029 μM, Vmax = 522.8 nmol min− 1 mg− 1). When 3SL was used as substrate, typical cooperative kinetics were found (S50 = 0.15 μM, Vmax = 154.3 nmol min− 1 mg− 1). The influenza inhibitor zanamivir inhibited the PorPV neuraminidase with IC50 of 0.24 μM. PorPV neuraminidase was activated by Ca2 + and inhibited by nucleoside triphosphates with the level of inhibition depending on phosphorylation level. The present results open possibilities to study the role of neuraminidase in the pathogenicity of PorPV infection and its potential inhibitors.