Sequential mutations in hemagglutinins of influenza B virus isolates: definition of antigenic domains

摘要: Abstract Comparative analysis of the amino acid sequences hemagglutinins (HAs) influenza B/Lee/40, B/Md/59, and B/HK/73 viruses has allowed examination molecular basis antigenic variation in type B viruses. As seen with A viruses, drift proceeds mostly through accumulation substitutions within HA1 portion HA molecule. However, rate observed among virus HAs appears to be significantly lower than HAs. The overall change HA1s studied is 2% per 10 years, whereas H3 vary by 9.2% years. were also examined relation three-dimensional model for A/Aichi/2/68 HA. When primary are compared, it that most important structural features HAs--such as sialic binding site, disulfide linkages, stem structure trimer--are conserved Regions identified where extensive have occurred three antigenically distinct locations these areas correspond regions proposed In addition, modulation may occur deletions glycosylation sites.