| Description | Endothelin-3, human, mouse, rabbit, rat TFA is a 21-amino acid vasoactive peptide that binds to G-protein-linked transmembrane receptors, ET-RA and ET-RB. Appearance:SolidIC50& Target:ET-RA, ET-RBBiological Activity:Endothelin-3, human, mouse, rabbit, rat TFA is a 21-amino acid vasoactive Endothelin-3, human, mouse, rabbit, rat TFA is a 21-amino acid vasoactive peptide that binds to G-protein-linked transmembrane receptors, ET-RA and ET-RB. Appearance:SolidIC50& Target:ET-RA, ET-RBBiological Activity:Endothelin-3, human, mouse, rabbit, rat TFA is a 21-amino acid vasoactive peptide that binds to G-protein-linked transmembrane receptors, ET-RA and ET-RB... Read More | Protein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 0.631 at 1.0 mg/ml for pure C1qMolecular Weight400,000 Da (18 chains)General DescriptionRat C1q is purified from pooled normal rat serum. C1q is part of the C1 complex, which is the first complement component in the classical pathway of Protein Purity≥85% by SDS PAGEExtinction CoeffA280 nm = 0.631 at 1.0 mg/ml for pure C1qMolecular Weight400,000 Da (18 chains)General DescriptionRat C1q is purified from pooled normal rat serum. C1q is part of the C1 complex, which is the first complement component in the classical pathway of complement. The C1 complex is a non-covalent assembly of three different proteins (C1q, C1r, and C1s) bound together in a calcium-dependent complex. C1q has six extended arms with domains at the end of each arm that bind to the Fc domains of immunoglobulins such as IgG or IgM. When antibodies bind toantigens, forming immune complexes, they cluster allowing two or more of the six C1q arms to bind to the Fc domains of antibodies. Rat IgG2 is very efficient when compared to IgG1 in activating complement (Medgyesi, G.A et., al., 1981). This is in contrast to the human system in which IgG1 activates complement but not IgG2 (Redpath, S. et. al., 1998). The binding of multiple arms of C1q to immune complexes causes the two C1r proteins in the complex (protease zymogens) to auto-activate. The activated C1r proteases cleave and activate the two C1s protease zymogens in the complex. The activated C1s cleaves complement component C4 releasing C4a and initiating covalent attachment of C4b to the activating surface. Activated C1s also cleaves C2 and the larger fragment of C2 binds to the surface-attached C4b forming C4b,C2a, the C3/C5 convertase of the classical pathway.Rat IgG1 cannot activate complement whereas rat IgG2 does.Physical Characteristics & StructureThe apparent molecular weight of rat C1q as determined by gel filtration has been reported to be 400,000 by Veerhuis, R. et al., (1985) and is calculated to be 420,000 based on its amino acid sequence. Rat C1q is a high molecular weight complex of 18 polypeptide chains. Each of the six arms of rat C1q contains three chains, an A chain (~30,000 daltons), a B chain (~28,000 daltons) and a C chain (~26,000 daltons) as determined by SDS/polyacrylamide gel electrophoresis (Wing, M.G. et al., (1993)).FunctionThe biological functions of C1q are described above in the General Description and Physical Characteristics sections.ApplicationsRat C1q can be used to coat ELISA plates to capture and quantitate immune complexes in samples from rat models used for studying immune complex related diseases and conditions.GeneticsNCBI Gene ID numbers for rat C1q are: C1q A chain (298566), C1q B chain (29687), and C1q C chain (362634). The genes for C1q chains A, B and C are all located on chromosome 5. The UniprotKB primary accession numbers for rat C1q are: C1q A chain (P31720), C1q B chain (P31721), and C1q C chain (P31722).Precautions/Toxicity/HazardsThis protein is purified from animal plasma/serum and therefore precautions appropriate for handling any animal blood-derived product must be used.ReferencesMedgyesi, G.A et., Miklos, K., Kulics, J., Fust, G., and Gergely, J. Bazin, H. (1981). Classes and subclasses of rat antibodies: reaction with the antigen and interaction of the complex with the complement system. Immunology 43, 171-176.Redpath, S., Michaelsen, T., Sandlie, I. and Clark, M. R. (1998). Activation of complement by human IgG1 and human IgG3 antibodies against the human leucocyte antigen CD52. Immunology 93, 595–600.Veerhuis, R., Van Es, L.A. and Daha, M.R. (1985). In vivo degradation of rat C1q induced by intravenous injection of soluble IgG aggregates. Immunology 54, 801-810.Wing, M.G., Seilly, D. J., Bridgman, D.J. and Harrison, R.A. (1993). Rapid isolation and biochemical characterization of rat C1 and C1q. Molecular Immunology 30, 433-440... Read More | Inquire | Inquire | Background：Tumor necrosis factor alpha (TNF-alpha ), also known as cachectin and TNFSF2, is the prototypic ligand of the TNF superfamily. It is a pleiotropic molecule that plays a central role in inflammation, immune system development, apoptosis, and lipid metabolism. Rat TNF-alpha consisitsBackground：Tumor necrosis factor alpha (TNF-alpha ), also known as cachectin and TNFSF2, is the prototypic ligand of the TNF superfamily. It is a pleiotropic molecule that plays a central role in inflammation, immune system development, apoptosis, and lipid metabolism. Rat TNF-alpha consisits of a 35 amino acid (aa) cytoplasmic domain, a 21 aa transmembrane segment, and a 179 aa extracellular domain (ECD). Within the ECD, rat TNF-alpha shares 94% aa sequence identity with mouse and 69%-76% with bovine, canine, cotton rat, equine, feline, human, porcine, and rhesus TNF-alpha. TNF-alpha is produced by a wide variety of immune, epithelial, endothelial, and tumor cells. TNF-alpha is assembled intracellularly to form a noncovalently linked homotrimer which is expressed on the cell surface. Cell surface TNF-alpha can induce the lysis of neighboring tumor cells and virus infected cells, and it can generate its own downstream cell signaling following ligation by soluble TNFR I. Shedding of membrane bound TNF-alpha by TACE/ADAM17 releases the bioactive cytokine, a 55 kDa soluble trimer of the TNF-alpha extracellular domain. TNF-alpha binds the ubiquitous 55-60 kDa TNF RI and the hematopoietic cell-restricted 80 kDa TNF RII, both of which are also expressed as homotrimers. Both type I and type II receptors bind TNF-alpha with comparable affinity, although only TNF RI contains a cytoplasmic death domain which triggers the activation of apoptosis. Soluble forms of both types of receptors are released and can neutralize the biological activity of TNF-alpha. Post-translational modificationsThe soluble form derives from the membrane form by proteolytic processing.The membrane form, but not the soluble form, is phosphorylated on serine residues.Dephosphorylation of the membrane form occurs by binding to soluble TNFRSF1A/TNFR1.O-glycosylated; glycans contain galactose, N-acetylgalactosamine and N-acetylneuraminic acid... Read More |