Interferon alpha A (alpha 2a), Recombinant, Human (IFNaA, IFNa2a)

At least 23 different variants of IFN-alpha are known. The individual proteins have molecular masses between 19-26kD and consist of proteins with lengths of 156-166 and 172 amino acids. All IFN-alpha subtypes possess a common conserved sequence region between amino acid positions 115-151 while the amino-terminal ends are variable. Many IFN-alpha subtypes differ in their sequences at only one or two positions. Naturally occurring variants also include proteins truncated by 10 amino acids at the carboxy-terminal end. Interferons (IFNs) appear early after viral infection locally and systematically to limit spread of viral infection. They also affect cell differentiation, growth, surface antigen expression and immunoregulation. There are three naturally occurring interferons: alpha, beta and gamma. Interferon alpha (IFN-alpha, IFNa) is also known as leukocyte interferon. B-lymphocytes are the predominant cellular producers of INF-alpha. IFN-alpha is derived from lymphoblastic tissue. IFN-alpha comprises a family of related, homologous proteins, each exhibiting a unique activity profile. The activities of the different IFN-alpha species on viruses can vary twenty fold or more. INF-alpha has a number of therapeutic applications in the treatment of various human cancers and diseases of viral origin. Recombinant IFN-alphas from both natural and synthetic genes bind to a common cell surface receptor and induce anti-viral activity in a variety of cell lines. When binding to discrete cell surface receptors on target cells, IFN-alpha induces rapid changes in Jak/Stat phosphorylation, which intiates the Jak/Stat signaling pathway. IFN-alpha signaling also involves production of DAG without an increased intracellular free calcium concentration and the subsequent activation of calcium-independent isoforms of PKC (beta and epsilon). All IFN-alpha signaling pathways lead to final alterations of gene expression, which mediate their pleiotropic biologic activities. IFN-alpha remains the most frequently used IFN for both research and clinical applications. It was first approved for combating malignancies. Anti-viral applications such as chronic Hepatitis B and C now make up the bulk of IFN sales. Different countries throughout the world have approved Hu-IFNa for different applications include: Chronic Hepatitis B, Chronic Hepatitis C, Hairy Cell Leukemia, Kaposi's Sarcoma (AIDS-related), Cutaneous T-cell Leukemia, Chronic Myeloid Leukemia, Renal Cell Carcinoma, Non-Hodgkin's Lymphoma, Adjuvant Therapy for Malignant Melanoma, Bladder Cell Carcinoma, Colon Carcinoma, Laryngeal Papillomatosis, Cervical Dysplasia, Condylomata Acuminata (Venereal Warts), Multiple Myeloma. Recombinant Human IFN-alpha 2a is a single, non-glycosylated, polypeptide chain containing 165 amino acids and having a molecular mass of 19241D. Interferon-alpha 2a gene was obtained from human leukocytes. Sequence: The sequence of the first five N-terminal amino acids was determined and was found to be Cys-Asp-Leu-Pro-Gln, conforming to the sequence of native human IFN-alpha. N-terminal methionine has been completely removed enzymatically. Biological Activity: IFN-alpha 2a is fully biologically active when compared to standard. The specific activity as determined in a viral resistance assay using bovine kidney MDBK cells was found to be 2.7 x 10e8. Storage and Stability: Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile ddH2O, 0.1% HSA or BSA. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.