IL-28B (human)

• Species; Human
• Expression Host: Baculovirus- insect cell
• Tag: His-tag
• Purity: 95%
• Molecular Weight: 22 kDa.
• Gene Accession Number: NM_172139

Purification and Quality Control
The C terminal His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified IL28B is greater than 95% homogeneous based on SDS-PAGE analysis.

Formulation and Storage
The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles.

Synonym
IFNL3; IL-28B; IL28C; interleukin 28B (interferon, lambda 3); interferon lambda;

Protein Sequence
MTGDCMPVLV LMAAVLTVTG AVPVARLRGA LPDARGCHIA QFKSLSPQEL QAFKRAKDAL EESLLLKDCK CRSRLFPRTW DLRQLQVRER PVALEAELAL TLKVLEATAD TDPALGDVLD QPLHTLHHIL SQLRACIQPQ PTAGPRTRGR LHHWLHRLQE APKKESPGCL EASVTFNLFR LLTRDLNCVA SGDLCV

Background
IL28B/IFN-lambda belongs to type III interferons that are class II cytokine receptor ligands (1). Expression of these cytokines can be induced by viral infection, such as influenza A. Lambda interferon renders epithelial cells of the respiratory and gastrointestinal tracts resistant to viral infections (6). Beside antiviral activity, mouse IFN-lambda also exhibit antitumor activity against B16 melanoma (7). Interleukin 28B gene encodes a cytokine distantly related to type I interferons and the IL-10 family. Interleukin 28A (IL28A), IL28B and interleukin 29 (IL29) are three closely related cytokine genes that form a cytokine gene cluster on a chromosomal region mapped to 19q13 (1, 2). These cytokines exert bioactivities that overlap those of type I IFNs, including antiviral activity and up-regulation of MHC class I antigen expression (2, 3). IL28B signals through a heterodimeric receptor complex that is composed of the IL-10 receptor beta (IL-10 R beta) and a novel IL-28 receptor alpha (IL-28 R alpha, also known as IFN-lambda R1). Binding to its receptor activated JAK tyrosine kinase, then leads to STAT phosphorylation and the formation of the IFN-stimulated regulatory factor 3(ISGF-3) transcription factor complex (1, 4). Mouse IL-28B cDNA encodes a 193 amino acid (aa) protein with a 19 aa signal peptide and a 174 aa mature protein that lacks N-glycosylation sites. Mature mouse IL-28B shares 64% aa sequence identity with human (5).

Image of SDS-PAGE /Western-blot