Activity-based screening system for the discovery of neuraminidase inhibitors using protein chip technology

Infectious bacteria or viral strain often expresses a family of neuraminidases to invade human body through the respiratory system. A role of the neuraminidase is cleaving specific glycosidic linkages of neuraminic acids when the pathogens are attached to cellular surface of host organisms. Inhibitors of neuraminidase are currently used as pharmaceutical agents for the treatment of pathogenic infections. In the present study, protein chip based screening system was established to discover inhibitory small-molecules of common neuraminidases in vitro. The chip system was basically operated by carbohydrate-protein interactions between transferrin sialoprotein and fluorescent dye-labeled lectin. By the catalytic action of neuraminidase, lectin was released from the transferrin with an accompanying loss of fluorescence signal. Actual inhibitory activity of the inhibitors was expressed by regaining fluorescence intensity on the sophisticatedly designed protein chip assay panel. Using this screening system, novel inhibitory compounds were found from commercially available chemical library.