Newcastle disease virus hemagglutinin-neuraminidase (HN) protein site II (NDV HN Site II)

The Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) protein is a multifunctional surface glycoprotein essential for viral infection, mediating attachment, neuraminidase activity, and fusion (F) protein triggering (Crennell et al., 2000). While Site I serves as the primary catalytic neuraminidase site, NDV HN possesses a distinct second binding site (Site II) located at the dimer interface of the globular heads (Yuan et al., 2011). This site specifically engages sialic acid residues on host cell receptors to induce the conformational changes necessary for activating the viral F protein, a prerequisite for membrane fusion and viral entry (Ibi et al., 2014). Because Site II is critical for the transition from attachment to fusion, it represents a significant target for antiviral drug development (Zaitsev et al., 2004). Inhibitors targeting this site, such as specific sialic acid analogs, aim to block the fusion-triggering mechanism, effectively neutralizing the virus's ability to infect host cells. Research indicates that Site II is highly conserved among NDV strains, suggesting that therapeutics targeting this interface could provide broad protection against various isolates (Jin et al., 2016).

Other names

NDV HN second receptor binding siteNDV HN dimer interface binding siteHemagglutinin-neuraminidase site IINDV HN Site 2

Competitive inhibition of sialic acid binding at the HN dimer interface, which prevents the conformational change required to trigger the viral fusion (F) protein.