RSV fusion (F) protein

Human respiratory syncytial virus (RSV) is a highly contagious member of the Pneumoviridae family of negative-sense, enveloped, RNA viruses. Over 80% of the population is exposed by the age of 2 years, making RSV among the most common causes of acute lower respiratory tract illness leading to hospitalization in children under 5 years of age. The RSV genome encodes 11 proteins, two of which, surface proteins F and G, are the major targets of neutralizing and non-neutralizing antibodies. RSV F, a class I viral fusion protein responsible for fusing the viral and host-cell membranes, is the target of palivizumab and the majority of neutralizing antibodies (nAb) raised by natural infection. RSV F is synthesized as a single chain inactive precursor (F0) which becomes activated upon cleavage by a furin-like protease into subunits F1 and F2, releasing a 27-amino acid glycopeptide called pep27.