Identification of lead inhibitors targeting influenza A virus nucleoprotein through surface plasmon resonance screening

Currently, many strains of influenza A virus have developed resistance against anti-influenza drugs, and it is essential to find new chemicals to combat this virus. The viral nucleoprotein (NP) is a major component of the ribonucleoprotein (RNP) complex for the transcription and replication of the virus. In this study, we have employed surface plasmon resonance direct binding screening on the influenza A NP and found a hit compound 16 that can subdue influenza RNP activities. Subsequently, two analogs (compounds 55 & 58) from compound 16 were identified which inhibit RNP activities of various influenza A subtypes and viral growth at micromolar levels. These analogs were also shown to directly interact with NP, with KD 12.0±1.25 and 41.6±1.93 μM respectively by surface plasmon resonance assay.