Respiratory syncytial virus fusion protein (prefusion conformation, site Ø) (RSV pre-F (site Ø))

The Respiratory Syncytial Virus (RSV) fusion (F) protein is a class I viral fusion glycoprotein essential for viral entry into host cells [1.1.1, 1.4.2]. It exists in two primary conformations: a metastable prefusion state (pre-F) and a stable postfusion state (post-F) [1.1.1, 1.5.1]. Site Ø (site zero) is a highly potent, neutralization-sensitive epitope located at the apex of the prefusion trimer, which is lost upon transition to the postfusion state [1.4.1, 1.5.1]. Most potent neutralizing antibodies in human serum target this specific site, making it a primary focus for vaccine development and monoclonal antibody prophylaxis [1.4.1, 1.4.5]. By targeting site Ø, therapeutic agents can effectively prevent the structural rearrangement required for membrane fusion, thereby neutralizing the virus before it enters the host cell [1.2.1, 1.4.3]. This target is central to recently approved vaccines and long-acting monoclonal antibodies designed to prevent RSV-associated lower respiratory tract disease in infants and older adults [1.2.2, 1.4.1].

Other names

RSV F proteinPrefusion F proteinSite zeroSite 0Antigenic site ØRSV-FFusion glycoprotein

Neutralization of viral entry by binding to the prefusion conformation of the RSV F protein at site Ø, which prevents the structural rearrangement into the postfusion state and blocks membrane fusion between the viral envelope and the host cell membrane [1.2.1, 1.4.3, 1.5.1].