Recombinant Influenza A Virus H1N1 Neuraminidase Protein, CF Summary
Details of Functionality
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/µg, as measured under the described conditions.
Spodoptera frugiperda, Sf 21 (baculovirus)-derived influenza a virus h1n1 Viral Neuraminidase protein Ser37-Lys469, with an N-terminal 6-His tag
>80%, by SDS-PAGE under reducing conditions and visualized by silver stain.
<1.0 EU per 1 μg of the protein by the LAL method.
48 kDa. Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
Substrate: 2’-(4-Methylumbelliferyl)-alpha -D-N-acetylneuraminic acid (Sigma, Catalog # M8639), 10 mM stock in DMSO
F16 Black Maxisorp Plate (Nunc, Catalog # 475515)
Fluorescent Plate Reader (Model: SpectraMax Gemini EM by Molecular Devices) or equivalent
Dilute rH1N1 Neuraminidase to 0.05 ng/µL in Assay Buffer.
Dilute Substrate to 400 µM in Assay Buffer.
Load 50 µL of 0.05 ng/µL rH1N1 Neuraminidase into the plate, and start the reaction by adding 50 µL of 400 µM Substrate. As a Substrate Blank load 50 µL of Assay Buffer and 50 µL of Substrate.
Read at excitation and emission wavelengths of 365 nm and 445 nm (top read), respectively in kinetic mode for 5 minutes.
Calculate specific activity:
Specific Activity (pmol/min/µg) =
Adjusted Vmax* (RFU/min) x Conversion Factor** (pmol/RFU)
amount of enzyme (µg)
*Adjusted for Substrate Blank **Derived using calibration standard 4-Methylumbelliferone (Sigma, Catalog # M1381).
rH1N1 Neuraminidase: 0.0025 µg
Substrate: 200 µM
This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.
Alternate Names for Recombinant Influenza A Virus H1N1 Neuraminidase Protein, CF
Neuraminidase (NA) and hemagglutinin (HA) are major membrane glycoproteins found on the surface of influenza virus. HA is a lectin that binds sialic acid on host cell membrane. NA is a sialic acid hydrolase that specifically clips off terminally located sialic acid on host cell surface. The two proteins are essential for the infectious cycle of the influenza virus. During initial infection, an influenza virus will hold onto an epithelial cell through HA-sialic acid interaction. At the end of an infectious cycle, the NA will cleave the sialic acid on the host cell membrane, releasing the formed viral particle from the HA-sialic acid bondage (1). The neuraminidase activity is also thought to help the virus penetrate mucus. Nine subtypes of NA have been identified, all of which are tetrameric and share a common structure consisting of a globular head, a thin stalk region, and a small hydrophobic region that anchors the protein in the virus membrane (2). The purified rvH1N1NA consists of amino acid residues 37 to 469 as deduced from the 1918 Spanish flu virus NA (A/Bervig_Mission/1/18) (3). It has a distinct N-glycan profile and is resistant to trypsin digestion (4).
Palese, P. & Compans, R. W. (1976) J. Gen. Virol. 33:159.
Colman, P. M. et al. (1983) Nature 303:41.
Reid, A. (2000) Proc. Natl. Acad. Sci. USA 97:6785.
Wu, Z.L. et al. (2009) Biochem. Biophys. Res. Comm. 379:749.
Publications for Neuraminidase (4858-NM)(2)
We have publications tested in 2 confirmed species: N/A, Virus.
We have publications tested in 1 application: Enzyme Assay.
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