Purity
>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method.
Activity
Measured in an anti-viral assay using HepG2 human hepatocellular carcinoma cells infected with encephalomyocarditis (EMC) virus. Sheppard, P. et al. (2003) Nat. Immunol. 4:63. The ED 50 for this effect is 1-5 ng/mL.
Source
Chinese Hamster Ovary cell line, CHO-derived Arg30-Val200, with the variant of Lys74Arg and a C-terminal 6-His tag
Accession #
N-terminal Sequence
AnalysisArg30
Predicted Molecular Mass
20.1 kDa
SDS-PAGE
22 kDa, reducing conditions
Carrier Free
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.
What formulation is right for me?
In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.
5259-IL |
| 5259-IL/CF |
Formulation Lyophilized from a 0.2 μm filtered solution in PBS, NaCl and EDTA with BSA as a carrier protein. | Formulation Lyophilized from a 0.2 μm filtered solution in PBS, NaCl and EDTA. | |
Reconstitution Reconstitute at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin. | Reconstitution Reconstitute at 100 μg/mL in sterile PBS. | |
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. | |
Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
| Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
|
Background: IL-28B/IFN-lambda 3
IL-28B (also named interferon-lambda 3, IFN-lambda 3), IL-28A (IFN-lambda 2) and IL-29 (IFN-lambda 1) are type III interferons that are class II cytokine receptor ligands (1-4). They are distantly related to members of the IL-10 family and type I IFN family (1- 4). Human IL-28B cDNA encodes a 200 amino acid (aa) protein with a 25 aa signal peptide and a 175 aa mature protein that lacks N-glycosylation sites. Mature human IL-28B shares 64% and 75% aa sequence identity with mouse and canine IL-28B, respectively, and is active across species (5). Human IL-28B shares 94% and 69% aa identity with human IL-28A and IL‑29, respectively (4). Type III interferons are widely expressed, but are mainly produced by antigen presenting cells in response to viruses and double-stranded RNA that interact with Toll-like receptors or RIG-1 family helicases (2-6). They signal through a widely expressed receptor that is a heterodimer of the IL-10 receptor beta (IL-10 R beta ) and IL-28 receptor alpha (IL-28 R alpha ; also called IFN-lambda R1) (2, 3, 7, 9). Interaction of either type I or type III IFNs with their receptors activates similar pathways, including JAK tyrosine kinase activation, STAT phosphorylation and formation of the IFN-stimulated regulatory factor 3 (ISGF-3) transcription factor complex (1-3). Both type I and III IFNs induce anti‑viral activity and up‑regulate MHC class I antigen expression (2-6). Cell lines responsive to type III IFNs are also responsive to type I IFNs, but in general, higher concentrations of type III IFNs are needed for similar in vitro responses (8). In vivo, however, type III IFNs enhance levels of IFN-gamma in serum, suggesting that the robust anti-viral activity of type III IFNs may stem in part from activation of the immune system (5, 7). Anti-proliferative and antitumor activity in vivo has also been shown for type III IFNs (9-11).
References:
Chen, Q. et al. (2006) Vitam. Horm. 74:207.
Sheppard, P. et al. (2003) Nat. Immunol. 4:63.
Kotenko, S.V. et al. (2003) Nat. Immunol. 4:69.
Bartlett, N.W. et al. (2005) J. Gen. Virol. 86:1589.
Ank, N. et al. (2006) J. Virol. 80:4501.
Onoguchi, K. et al. (2007) J. Biol. Chem. 282:7576.
Siebler, J. et al. (2007) Gastroenterology 132:358.
Meager, A. et al. (2005) Cytokine 31:109.
Lasfar, A. et al. (2006) Cancer Res. 66:4468.
Sato, A. et al. (2006) J. Immunol. 176:7686.
Zitzmann, K. et al. (2006) Biochem. Biophys. Res. Commun. 344:1334.
Long Name:
Interleukin 28B
Entrez Gene IDs:
282617 (Human); 338374 (Mouse)
Alternate Names:
interleukin-28B; IFN-lambda 3; IL28B; IL-28B; IL28C; interferon, lambda 3
