Tumor necrosis factor (TNF, cachexin or cachectin and formally known as tumor necrosis factor-alpha) is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction. The primary role of TNF is in the regulation of immune cells. TNF is also able to induce apoptotic cell death, to induce inflammation, and to inhibit tumorigenesis and viral replication. Dysregulation and, in particular, overproduction of TNF have been implicated in a variety of human diseases, as well as cancer. TNF is primarily produced as a 212aa-long type II transmembrane protein arranged in stable homotrimers. From this membrane-integrated form the soluble homotrimeric cytokine (sTNF) is released via proteolytic cleavage by the metalloprotease TNF alpha converting enzyme (TACE, also called ADAM17). The soluble 51kD trimeric sTNF tends to dissociate at concentrations below the nanomolar range, thereby losing its bioactivity. The 17kD TNF protomers (185aa-long) are composed of two antiparallel beta-pleated sheets with antiparallelbeta-strands, forming a 'jelly roll' beta-structure, typical for the TNF family, but also found in viral capsid proteins. TNF is produced mainly by macrophages, but they are produced also by a broad variety of other cell types including lymphoid cells, mast cells, endothelial cells, cardiac myocytes, adipose tissue, fibroblasts, and neuronal tissue. Large amounts of TNF are released in response to lipopolysaccharide, other bacterial products, and Interleukin-1 (IL-1).
Function:Cytokine that binds to TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR. It is mainly secreted by macrophages and can induce cell death of certain tumor cell lines. It is potent pyrogen causing fever by direct action or by stimulation of interleukin-1 secretion and is implicated in the induction of cachexia, Under certain conditions it can stimulate cell proliferation and induce cell differentiation. Recombinant TNF is used as an immunostimulant under the INN tasonermin.
Source:Recombinant protein corresponding to human TNF-alpha, a single, non-glycosylated, polypeptide chain containing 158aa, expressed in E. coli.
Molecular Weight:~17.48kD
Biological Activity:Determined by the cytolysis of mouse L929 cells in the presence of Actinomycin D is ~0.05ng/ml.
Specific Activity:~2x107IU/mg
AA Sequence:The sequence of the first five N-terminal aa was determined and was found to be Met-Val-Arg-Ser-Ser
Subcellular Location: Cell membrane; single-pass type II membrane protein. Tumor necrosis factor, soluble form: secreted.
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°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.
仕様
Size：10ug
Source Antigen：Recombinant, E. coli
Grade：Highly Purified
Purity：Highly Purified (~98%)
Form：Supplied as a liquid in 20mM PBS, pH 7.2, 10mM sodium chloride.
