Interferon-γ, human (hIFN-γ) recombinant (E. coli) Roche

Human interferon-γ (hIFN-γ) can be used to investigate IFN-γ activities in human cell systems.

Primary structure
The primary structure of recombinant human IFN-γ (143 amino acids) is identical to that of natural human IFN-γ (146 amino acids), but recombinant IFN-γ has three amino acids less and is not glycosylated.
Glycosylation is not essential for biological activity.
Molecular Weight
16,700 Da
Specific activity/EC ₅₀ :
>2 x 10 ⁷ U/mg, <0.05 ng/ml (hIFN- Υ , NIH, reference standard, Gg 23–901-530), at least the same specific activity (EC ₅₀ ) compared to the indicated standard is guaranteed.
EC ₅₀ definition/Unit definition
The amount of hIFN-γ that is required to produce equivalent antiviral activity to that expressed by 1 unit of the NIH IFN-γ reference standard (Gg 23– 901-530) (WISH cells-EMC virus/cytopathic effect) (1 unit equals ≤0.05 ng/ml).
Species specificity
Human IFN-γ is effective on human cells, but not on mouse or rat cells.

IFN-γ is produced by T-lymphocytes stimulated by antigen or by T-cell mitogens (4). Under denaturating conditions, recombinant human IFN-γ has a molecular weight of 17,100. Under nondenaturating conditions the molecular weight values range from 32,000 to 73,000 indicating that recombinant human IFN-γ exists as a dimer or higher oligomers (5). A broad range of biological activities has been attributed to IFN-γ  (e.g., the establishment of the antiviral state, immunoregulatory functions, antiproliferative effects) (4, 9). IFNs are defined solely in terms of their antiviral activity, however, IFN-γ can also inhibit cell growth. The anti-proliferative effects of IFN-γ are superior to those of either IFN-α or IFN-β. Growth inhibition is dependent on cell type, dose, and length of exposure. One of IFN-γ’s primary functions might be as an immunoregulatory agent: IFN-γ induces MHC antigens on many cells, Fc-receptors on monocytes and macrophages, IL-2 receptors on T-cells, enhances activity of macrophages, polymorphonuclear leukocytes, T-lymphocytes, and NK-cells (MAF), and is also involved in the regulation of B-cells (6–9).

References
 

1. Devos, R. et al. (1982) Nucleic Acids Res. 10, 2487-2501.
2. Gray, P. W. et al. (1982) Nature 295, 503-508
3. Rinderknecht, E., O'Connor, B. H. & Rodriguez, H. (1984) J. Biol. Chem.259, 6790-6797.
4. Langer, J. A. & Pestka, S. (1985) Pharmac. Ther. 27, 371-401.
5. Nagata, K. et al. (1987) J. Interferon Res. 7, 313-320.
6. Kirchner H. (1984) Springer Semin. Immunopathol. 7, 347-374.
7. Balkwill, F R. (1986) Microbiol. Sciences 3, 229-233.
8. Bonnem, E. M. & Oldham, R. K. (1987) J. Biol. Response Mod. 6, 275-301.
9. Pestka, S. et al. (1987) Ann. Rev. Biochem. 56, 727-777.

100,000 U/ml or 1,000,000 U/ml in 0.1 M phosphate buffer saline (PBS) (pH 7.0), 2.5% sucrose (w/v), and 2.5% human serum albumin (HSA) (w/v), filtered through a 0.2 µm pore size membrane.

The raw material used for this preparation was tested for HBs antigen and for the presence of antibodies to HIV-1, HIV-2, and HCV found to be negative.
Purity
Recombinant hIFN-γ is >95% pure as determined by SDS-PAGE.
Endotoxin level
  <0.1 EU/µg (LAL-test), <10 EU/ml (LAL-test)
Note: 1 EU corresponds to 0.1 ng