Variola virus protein A27 (A27) (A27)

Variola virus protein A27 is a multifunctional structural protein located on the envelope of the mature virion (MV) of the smallpox virus. It plays a critical role in the viral life cycle by mediating the initial attachment of the virus to host cells through its binding to cell surface heparan sulfate proteoglycans [3, 6]. Beyond attachment, A27 serves as a molecular scaffold, anchoring the A26 protein to the virion and interacting with the A17 protein to ensure proper membrane association [4, 16]. It is also essential for the morphogenesis of the extracellular enveloped virus (EEV) form, which is responsible for long-range viral dissemination within the host [5, 8]. As a prominent surface antigen, A27 is a major target for the host's neutralizing antibody response and is a key component of both traditional and next-generation smallpox vaccines [6, 7]. While no small-molecule drugs currently target A27 directly, it is a primary focus for the development of therapeutic monoclonal antibodies and is a major constituent recognized by Vaccinia Immune Globulin (VIG) [3, 13]. Inhibiting A27 function effectively blocks viral entry and reduces the spread of infection, making it a high-priority target for anti-poxvirus countermeasures [4, 8].

Other names

A27L proteinHeparin-binding protein14 kDa envelope proteinA30A31

Neutralization of mature virions and inhibition of viral attachment to heparan sulfate on host cells.