About Influenza A Hemagglutinin (HA) Trimer (A/California/06/2009, H1N1) Recombinant Protein

Influenza A (H1N1) viruses are important human respiratory pathogens responsible for seasonal influenza outbreaks and the 2009 H1N1 pandemic (H1N1pdm09). The A/California/06/2009 strain is one of the prototype pandemic viruses and has been extensively used as a reference strain for vaccine development, antigenic characterization, and influenza research. The viral hemagglutinin (HA) glycoprotein is the major surface antigen responsible for receptor binding and membrane fusion, making it the principal target of neutralizing antibodies and seasonal influenza vaccines.

eEnzyme's Influenza A Hemagglutinin (HA) Trimer (A/California/06/2009, H1N1) Recombinant Protein is expressed in HEK293 cells and comprises the full-length ectodomain (amino acids 18–530) with a C-terminal 6×His tag and an engineered trimerization domain to stabilize the native trimeric structure of HA. The trimeric configuration more closely resembles the functional HA spikes present on the influenza virion, preserving conformational epitopes recognized by neutralizing antibodies. The recombinant protein exhibits >95% purity (SDS-PAGE) and native mammalian glycosylation, making it suitable for ELISA, Western blotting, neutralization studies, receptor-binding assays, vaccine development, structural biology, and diagnostic assay development.

Applications

Biological Significance of Trimeric Influenza A Hemagglutinin

Hemagglutinin functions as a homotrimer on the influenza virus surface, where each monomer contributes to the formation of the receptor-binding and membrane fusion machinery. Following attachment to α2,6-linked sialic acid receptors on host epithelial cells, HA undergoes a low pH-induced conformational change within endosomes that drives fusion of the viral and cellular membranes. Because most protective and broadly neutralizing antibodies recognize conformation-dependent epitopes present on the native trimer, recombinant trimeric HA provides a more physiologically relevant antigen than monomeric HA for immunological studies and vaccine evaluation.

The Influenza A Hemagglutinin (HA) Trimer (A/California/06/2009, H1N1) Recombinant Protein provides a high-quality research reagent for investigating influenza virus biology, evaluating vaccine-induced immune responses, screening neutralizing antibodies, and developing next-generation influenza vaccines and therapeutics. Its stabilized trimeric structure, native mammalian glycosylation, and preserved conformational epitopes make it particularly valuable for influenza immunology, structural biology, and translational vaccine research.