| Description | Leucine Aminopeptidase belongs to the family of metalloprotease.Application:Leucine Aminopeptidase, microsomal from porcine kidney has been used in the isolation of neprilysin (NEP) from rodent brain-C5 and for peptide digestion | 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 | Purity:>95%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard Purity:>95%, by SDS-PAGE visualized with Coomassie® Blue Staining.Description：CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard phenotype marker for the identification of T cell populations. Mature feline CD4 consists of a 388 amino acid (aa) extracellular region containing four immunoglobulin-like domains, a 22 aa transmembrane segment, and a 40 aa cytoplasmic domain. Within the ECD, feline CD4 shares 70%, 58%, 50%, and 48% aa sequence identity with canine, human, mouse and rat CD4, respectively. CD4 is expressed along with CD8 on double positive T cells during their development in the thymus. Either CD4 or CD8 expression is then lost, giving rise to single positive (SP) CD4+ or CD8+ mature T cells. CD4+ SP cells, also known as T helper cells, further differentiate into multiple subsets of CD4+ cells including Th1, Th2, Th17, Tfh, and Treg cells which regulate humoral and cellular immunity. CD4 is reexpressed on circulating CD8+ T cells upon activation and contributes to their cytotoxic effector activity. In human, CD4 is additionally expressed on macrophages, neutrophils, monocytes, NK cells, and neurons and glial cells in the brain. Similar CD4 distribution between species cannot be assumed as demonstrated by its presence on macrophages in human and rat but not in mouse. CD4 binds directly to MHC class II molecules on antigen presenting cells. This interaction contributes to the formation of the immunological synapse which is focused around the TCR-MHC class II-antigenic peptide interaction. Palmitoylation of two cysteine residues in the cytoplasmic tail of CD4 promotes the localization of CD4 in lipid rafts and its ability to augment TCR signaling via activation of the tyrosine kinase Lck. CD4 also functions as a chemotactic receptor for IL-16 and, in human, as a coreceptor for the gp120 surface glycoprotein of HIV-1... Read More | Purity:>95%, by SDS-PAGE visualized with Coomassie® Blue StainingDescription:Human B7 homolog 3 (B7-H3) is a member of the B7 family of immune proteins that provide signals for the regulation of immune responses. Other family members include B7-1, B7-2, B7-H1/PD-L1, B7-H2, and PD-L2. B7 Purity:>95%, by SDS-PAGE visualized with Coomassie® Blue StainingDescription:Human B7 homolog 3 (B7-H3) is a member of the B7 family of immune proteins that provide signals for the regulation of immune responses. Other family members include B7-1, B7-2, B7-H1/PD-L1, B7-H2, and PD-L2. B7 family proteins are type I transmembrane immunoglobulin (Ig) superfamily members that contain extracellular Ig V‑like and Ig C‑like domains with a short cytoplasmic tail. Among the family members there is about 20 - 40% amino acid (aa) sequence identity. B7-H3 was initially reported to be a 316 aa type I transmembrane precursor protein that contained a signal sequence, an extracellular region with one V‑type and one C‑type Ig domain, a transmembrane segment and a short cytoplasmic tail. Subsequent studies have identified a second 110 kDa form whose precursor is 534 aa in length. Termed 4IgB7-H3 or B7-H3b, this molecule has two additional Ig-like domains (one V‑type and one C‑type) and shows a ubiquituous expression pattern. It would appear that the human 4Ig form is the principal, if not the only form of B7-H3. Its precursor contains a 26 aa signal sequence, a 435 aa extracellular region, a 31 aa transmembrane domain, and a 42 aa cytoplasmic tail. The four Ig-like domains alternate between V‑type and C‑type, and apparently are the consequence of a V‑C type tandem duplication. B7-H3b is expressed on dendritic cells as well as activated T, B and NK cells. The mouse gene differs from that of human in that it cannot code for four Ig-like domains; only a V‑type:C‑type pair. Human B7-H3b binding to an undefined receptor has shown to be inhibitory to NK cell illing and cytokine release. It also seems to be required for late stage osteoblast differentiation... Read More | Purity>97% by SDS-PAGE and HPLC analyses.FunctionMay be involved in macrophage-mediated cellular proliferation. It is mitogenic for fibroblasts and smooth muscle but not endothelial cells. It is able to bind EGF receptors with higher affinity than EGF itself and is a far more potent mitogen for Purity>97% by SDS-PAGE and HPLC analyses.FunctionMay be involved in macrophage-mediated cellular proliferation. It is mitogenic for fibroblasts and smooth muscle but not endothelial cells. It is able to bind EGF receptors with higher affinity than EGF itself and is a far more potent mitogen for smooth muscle cells than EGF. Also acts as a diphtheria toxin receptor.Background:Human HB-EGF (Heparin-Binding EGF-like growth factor) is a 12-16 kDa member of the EGF family of peptide growth factors (1-3). Also known as the DTR (diphtheria toxin receptor), it is further classified as a group 2 ErbB ligand based on its ability to activate both the EGF/ErbB1 and ErbB4 receptors (4, 5). HB-EGF is synthesized as a 208 amino acid (aa) type I transmembrane preproprecursor (1, 6). It contains a 19 aa signal sequence, a 43 aa prosegment, an 86 aa mature region (aa 63-148), an 11 aa juxtamembrane cleavage peptide, a 24 aa transmembrane segment, and a 25 aa cytoplasmic tail (aa 184-208). As an integral membrane protein, HB-EGF is expressed as a 19-27 kDa protein in mammalian cells (7-9). The variability in molecular weight (MW) is attributed to heterogeneity in glycosylation and/or the utilization of multiple proteolytic cleavage sites during maturation. Mature HB-EGF is a soluble peptide that arises from proteolytic processing of the transmembrane form. It possesses an EGF-like domain between aa 104-144, and a heparin-binding motif between aa 93‑113. Although the aa range for "mature" HB-EGF is typically stated to be Asp63-Leu148, potential N-terminal start (cleavage) sites also exist at Gly32, Arg73, Val74, Ser77 and Ala82 (8, 10-12). Thus, differential processing (in part) likely accounts for the 16-23 kDa range in MW noted for mammalian-derived mature HB-EGF. Proteases suggested to contribute to HB-EGF processing include TACE, MMP-3 and -7, ADAM-17 and ADAM-12 (11, 13-16). When expressed recombinantly in E.coli, HB-EGF (aa 73-148) runs at 14 kDa in SDS-PAGE; when expressed in Baculovirus, HB-EGF (aa 63-148, 77-148 and 32-148) runs at 18 kDa, 15 kDa, and 19 kDa respectively (8, 12, 17). Over aa 63-148, human HB-EGF- shares 76% and 73% aa sequence identity with rat and mouse HB-EGF, respectively (1, 18). Cells known to express HB-EGF include bronchial epithelium (19), visceral and vascular smooth muscle (20, 21), CD4+ T cells (22), cardiac muscle (23), glomerular podocytes (24), keratinocytes (13) and IL-10-secreting regulatory macrophages (25). As noted earlier, HB-EGF is known to bind to both 170 kDa EGFR and 180 kDa ErbB4, and through heterodimerization, ErbB2 (13, 26). Activity associated with ErbB4 binding appears to be limited to non-mitogenic actions, while EGFR binding induces both mitogenic and non-mitogenic activity... Read More |