TNF alpha, Tumor Necrosis Factor-alpha, human: Human Tumor Necrosis Factor-alpha
Tumor necrosis factor alpha (TNF-α), also called cachectic, is produced by neutrophils, activated lymphocytes, macrophages, NK cells, LAK cells, astrocytes endothelial cells, smooth muscle cells and some transformed cells. TNF-α occurs as a secreted, soluble form and as a membrane-anchored form, both of which are biologically active. The naturally-occurring form of TNF-α is glycosylated, but non-glycosylated recombinant TNF-α has comparable biological activity. The biologically active native form of TNF-α is reportedly a trimer. Human and murine TNF-α show approximately 79% homology at the amino acid level and cross reactivity between the two species. Two types of receptors for TNF-α have been described and virtually all cell types studied show the presence of one or both of these receptor types.
Source: Escherichia coli.
Molecular Weight: Approximately 17.5 kDa. The recombinant protein preparation is a mixture of a 158 amino acid residue form containing an N-terminal methionine and a 157 amino acid residue form with the sequence of mature human TNF-α.
Purity: >95% by SDS-PAGE and HPLC analyses.
Biological Activity: Fully biologically active when compared to standard. The Specific Activity is ≥2.0 × 107 IU/mg as determined by the cytolysis of murine L929 cells in the presence of Actinomycin D.
Physical Appearance: Sterile Filtered White lyophilized (freeze-dried) powder.
Formulation: Lyophilized from a 0.2mm filtered concentrated (1mg/ml) solution in PBS, pH 7.0.
AA Sequence: VRSSSRTPSD KPVAHVVANP QAEGQLQWLN RRANALLANG VELRDNQLVVPSEGLYLIYS QVLFKGQGCP STHVLLTHTI SRIAVSYQTK VNLLSAIKSP CQRETPEGAE AKPWYEPIYL GGVFQLEKGD RLSAEINRPD YLDFAESGQV YFGIIAL
Endotoxin: Less than 1EU/mg of rHuTNF-α as determined by LAL method.