Influenza, commonly known as “the flu”, is an infectious disease of birds and mammals caused by RNA viruses of the family Orthomyxoviridae, the influenza viruses. The virus is divided into three main types (Influenza virus A, Influenza virus B, and Influenza virus C), which are distinguished by differences in two major internal proteins (hemagglutinin (HA) and neuraminidase (NA), which are the most important targets for the immune system. The type A viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease.
Influenza virus neuraminidase (NA)
Influenza virus neuraminidase (NA) is a mushroom-shaped tetramer of identical subunits. Each of the subunits that form the head of the mushroom is made up of a propeller-like structure, the blades of which are formed by four antiparallel strands of β-structure. The enzyme active site is located at roughly the center of each subunit. During virus replication, Influenza virus neuraminidase removes sialic acid from cellular glycoproteins and glycolipids and from both of the virus glycoproteins. As a result, newly assembled viruses are prevented from binding to the infected cell surface and from aggregating with each other through HA-sialic acid interactions. Instead, they are released from the cell to infect new cells and spread the infection.The structure of NA has been reviewed by Gamblin and Skehel in 2010.
This Influenza virus neuraminidase protein is derived from the NA sequence of the A/Thailand/1(KAN-1)/2004 (H5N1) strain, (Accession # H8PF47), expressing His36- Lys449, and is fused with a polyhistidine tag at the C-terminus. The total calculated MW is 46.1kDa. The Influenza virus neuraminidase protein is expressed in HEK293 cells, and reduced protein migrates as a band of 48kDa.
****SHIPPING AND STORAGE NOTIFICATION: This recombinant protein has been lyophilised to maximise stability. It is shipped at ambient temperature, and may be stored for up to 1 year at 4C prior to reconstitution. Following reconstitution it should be stored at -80C. Extensive stability tests have shown no negative effects on antigen performance for 7 days of shipping at ambient temperature.