Neuraminidase (NA) and hemagglutinin (HA) are the two predominant membrane glycoproteins found on the surface of an influenza virus particle. They are essential for the infectious cycle of the virus. HA recognizes and binds to the sialic acid on the host cell membrane to initiate a viral infection. NA cleaves the sialic acid at the end of the cycle, allowing the progeny virus to leave the host and initiate the next round of infection (1). In the early stage of an infection, NA may also assist in viral penetration of the mucus layer in the airway of a host. Nine subtypes of NA (N1 to N9) have been identified, all of which are believed to be tetrameric and share a basic structure consisting of a globular head, a thin stalk region, and a small hydrophobic region that anchors the protein in the virus membrane (2). Glycosylation has also found been important for the stability and activity of these enzymes (3, 4). According to a recent structure determination (5), there are two genetically distinct groups of neuraminidases from influenza type A viruses, with the N1 and N2 neuraminidases representing the two groups. Due to their critical role in the infectious cycle of a virus, influenza viral neuraminidases are frequently used as targets for drug design. In fact, both Tamiflu and Relenza, anti-influenza drugs, are neuraminidase inhibitors. Our recombinant H5N1 neuraminidase is based on the avian virus isolated from the 2004 outbreaks of the H5N1 virus in Vietnam and Thailand (6). H5N1 avian virus is one of the most lethal viruses in history (7, 8) with an accumulative death rate of 59% from 2003 to 2012 according to the World Health Organization (9). To produce active recombinant enzyme, a tetramerization domain from the vasodilator-stimulated phosphoprotein (10) was inserted at the N-terminus to assist in oligomerization of the protein. We found that the activity of the recombinant H5N1 neuraminidase is activated by Ca2+ and inactivated by Zn2+, Cu2+ and Fe2+.
Source:Recombinant protein corresponding toInfluenze A Virus H5N1 Neuraminidase, Ser37-Lys449, with an N-terminal vasodilator-stimulated phosphoprotein tetramerization domain and a C-terminal 6-His tag, NS0-derived.
Molecular Weight:~58-65kD
Endotoxin:<0.1EU/1ug (LAL method).
Biological Activity:Measured by its ability to cleave a fluorogenic substrate, 2’-(4-Methylumbelliferyl)-alpha -D-N-acetylneuraminic acid. The specific activity is >2,500 pmol/min/ug, as measured under the described conditions.
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：10ug
Source Antigen：Recombinant, NS0 cells
Grade：Highly Purified
Purity：~95% (SDS-PAGE)
Form：Supplied as a liquid in Tris, NaCl, glycerol.
