There are four types of Influenza (flu) viruses: type A, B, C, and D. Influenza A and B viruses are routinely spread in people and other mammals, while also known for seasonal flu epidemics each year. Influenza B is Betainfluenzavirus in the virus family Orthomyxoviridae. Influenza B is classified into two distinct lineages, B/Victoria and B/Yamagata1. Influenza B can be even further classified into specific clades (also known as groups) and sub-clades (also known as sub-groups) based on similarity of their HA/NA gene sequences1.
The Nucleocapsid protein or nucleoprotein (NP) of influenza virus B negative-strand RNA’s primary function is to encapsulate the virus genome for the purpose of RNA transcription, replication and packaging2. Specifically, NP is the most abundant viral protein in infected cells2, therefore the NP can be and has been used for anti-influenza drug development3 The NP of influenza A and B viruses share up to 38% of their amino acid sequence, indicating region functionality differences at the amino acid level4.
Purified No Carrier Protein
≥95% by SDS Page
≥ 5.0 mg/ml
<0.10 EU per 1 μg of the protein by the LAL method
Protein Accession No.
Amino Acid Sequence
MSNMDIDGINTGTIDKTPEEITPGTSGTTRPIIRPATLAPPSNKRTRNPSPERATTSSED DVGRKTQKKQTPTEIKKSVYNMVVKLGEFYNQMMVKAGLNDDMERNLIQNAHAVERILLA ATDDKKTEFQKKKNARDVKEGKEEIDHNKTGGTFYKMVRDDKTIYFSPIRITFLKEEVKT MYKTTMGSDGFSGLNHIMIGHSQMNDVCFQRSKALKRVGLDPSLISTFAGSTIPRRSGAT GVAIKGGGTLVAEAIRFIGRAMADRGLLRDIKAKTAYEKILLNLKNKCSAPQQKALVDQV IGSRNPGIADIEDLTLLARSMVVVRPSVASKVVLPISIYAKIPQLGFNVEEYSMVGYEAM ALYNMATPVSILRMGDDAKDKSQLFFMSCFGAAYEDLRVLSALTGTEFKPRSALKCKGFH VPAKEQVEGMGAALMSIKLQFWAPMTRSGGNEVGGDGGSGQISCSPVFAVERPIALSKQA VRRMLSMNIEGRDADVKGNLLKMMNDSMAKKTSGNAFIGKKMFQISDKNKTNPVEIPIKQ TIPNFFFGRDTAEDYDDLDY
State of Matter
Predicted Molecular Mass
The predicted molecular mass is ~65 kDa.
This recombinant protein is aseptically packaged and formulated in 0.01 M phosphate buffered saline (PBS) pH 7.2 - 7.4, 150 mM NaCl with no carrier protein, potassium, calcium or preservatives added.
Storage and Stability
This recombinant protein may be stored as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at -80°C. Avoid Repeated Freeze Thaw Cycles.
Country of Origin
Next Day Ice Pack
NCBI Gene Bank
References & Citations
1. Types of Influenza viruses (2019) Center for Disease Control and Prevention.
2. Hu Y, Sneyd H, et al. (2017) Curr Top med Chem. 2017; 17(20): 2271–2285.
3. Portela A, Digard P. (2012) J. Gen Virol. 2002 Apr;83(Pt 4):723-734.
4. Sherry L, Smith M, et al. (2014) Journal of Virology. 2014; 88(21); 12326-12338. DOI https://doi.org/10.1128/JVI.01542-14
IMPORTANT Use lot specific datasheet for all technical information pertaining to this recombinant protein.
Products are for research use only. Not for use in diagnostic or therapeutic procedures.