You searched for: Proteins and Peptides

Supplier: Stemcell Technologies

Interleukin 6 receptor (IL-6R) alpha is a type I transmembrane glycoprotein that forms a complex with type I transmembrane signal transducer protein gp130 (CD130) and mediates the biological activities of IL-6. IL-6 binds to the membrane-bound non-signaling IL-6R alpha (mIL-6R), and the complex binds to two molecules of gp130 and leads to ‘classical’ IL-6-signal transduction, which includes activation of JAK/STAT, ERK, and PI3K signal transduction pathways (Scheller et al.). In contrast, a soluble form of IL-6R alpha (sIL-6R), which comprises the extracellular portion of the receptor, binds to the secreted IL-6 to form a complex that promotes bioavailability of IL-6. The complex of IL-6 and sIL-6R can bind to gp130 on cells that do not express the IL-6R and are unresponsive to IL-6. This process is known as trans-signaling (Hunter and Jones; Rose-John S). sIL-6R regulates both local and systemic IL-6-mediated events. Elevated levels of sIL-6R have been documented in several disease conditions such as rheumatoid arthritis, myeloma, and Crohn’s disease (Jones et al.; Mihara et al.).

Supplier: Stemcell Technologies

Use Interferon beta (IFN-β) to modulate the activity of genes that control dendritic cell activation, T cell survival, NK cell activation, chemokine expression, lymph node retention, and antiproliferative and antiviral effects (Dunn et al. Nat Rev Immunol, 2006). IFN-β binds to a receptor complex composed of IFNAR1 and IFNAR2, and initiates signal transduction via the JAK/STAT pathway. It is predominantly produced by fibroblasts, with smaller amounts from plasmocytoid dendritic cells. Macrophages and endothelial cells secrete IFN-β in response to viral infection (Reder and Feng. Front Immunol, 2013). IFN-β suppresses Th17 cells by affecting expression of IL-4, IL-10, and IL-27, and is a first-line treatment for multiple sclerosis. IFN-β was also shown to expand regulatory T cells and limit T cell trafficking to the central nervous system (Inoue and Shinohara. Immunology, 2013). Of the two IFN-β variants (IFN-β1 and IFN-β3), this product is the IFN-β1 form.

Supplier: Stemcell Technologies

Platelet-derived growth factor (PDGF) is a dimeric glycoprotein consisting of two disulfide bridge-stabilized polypeptide chains, A and B, which are assembled as heterodimers (PDGF-AB) or homodimers (PDGF-AA and PDGF-BB) (Fretto et al.; Westermark and Heldin). PDGF signals through the receptor tyrosine kinases PDGFRalpha and PDGFRbeta. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src, and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin- like fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). It has been shown that PDGF-AB together with 5-Azacytidine (Catalog #72012), induces the conversion of mature bone and fat cells into tissue-regenerative multipotent stem cells (Chandrakanthan et al.).

Supplier: Adipogen

Interleukin-21 (IL-21) is a key factor in the transition between innate and adaptive immune responses secreted by activated T cells. The IL-21 receptor (IL-21R) is expressed in lymphoid tissue, in particular by NK, B, T and dendritic cells, macrophages and endothelial cells. Recent evidence suggests that IL-21 plays a supportive role in the proliferation of T and B cells and influences the cytolytic activity of natural killer cells. IL-21 has been shown to up-regulate genes associated with innate immunity and to inhibit the differentiation of naïve T helper cells. IL-21 specifically inhibits IFN-gamma production from developing TH1 cells and is preferentially expressed by TH2 cells. Furthermore IL-21 has been identified as a growth and survival factor for human myeloma cells. IL-21/IL-21R interactions have a unique role in sequentially activating both innate and adaptive immune responses against poorly immunogenic tumors, leading to tumor rejection that is perforin dependent but IFN-gamma independent.

Supplier: Adipogen

IL-36alpha (IL-1F6), IL-36beta (IL-1F8) and IL-36gamma (IL-1F9) bind to IL-36R (IL-1Rrp2) and IL-1RAcP, activating similar intracellular signals as IL-1 and are inhibited by IL-36Ra. The expression of IL-36 cytokines has been shown to occur at different sites including the lung and skin and can be derived from diverse cell types including keratinocytes, bronchial epithelium as well as macrophages, monocytes and different T cell subsets. IL-36 family members induce the production of proinflammatory cytokines, including IL-12, IL-1beta, IL-6, TNF-alpha and IL-23 in BMDC and CD4 T cells, thus promoting neutrophil influx, dendritic cell (DC) activation, polarization of T helper type 1 (Th1) and IL-17-producing T cells (alphabeta T cells and gammadelta T cells) and keratinocyte proliferation. These cytokines may represent potential targets for immune-mediated inflammatory conditions or, alternatively, could be used as adjuvants in vaccination. IL-36gamma is also induced in the lung in various models of asthma and can be produced by bronchial epithelial cells in response to viral infection, smoke or inflammatory cytokines.

Supplier: Stemcell Technologies

Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to heterotrimeric receptors consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). High IL-2 levels in serum are associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer, though no known disease can be directly attributed to the lack or excess of IL-2 (Gaffen and Liu).

Supplier: Stemcell Technologies

Granulocyte colony-stimulating factor (G-CSF) is a member of the CSF family of glycoproteins that regulate hematopoietic cell proliferation, differentiation, and function. It is a key cytokine involved in the production of neutrophils and the stimulation of granulocyte colony formation from hematopoietic progenitor cells (Metcalf and Nicola). G-CSF causes a range of effects including a transient reduction of SDF-1 expression (Petit et al.), the activation of metalloproteases that cleave VCAM-1 (Levesque et al.), and the release of norepinephrine from the sympathetic nervous system (Katayama et al.), leading to the release or mobilization of hematopoietic stem cells from the bone marrow into the periphery. The G-CSF receptor is expressed on a variety of hematopoietic cells, including myeloid-committed progenitor cells, neutrophils, granulocytes, and monocytes. In addition to hematopoietic cells, G-CSF is also expressed in cardiomyocytes, neuronal cells, mesothelial cells, and endothelial cells. Binding of G-CSF to its receptor leads to activation of the JAK/STAT, MAPK, PI3K, and AKT signal transduction pathways. This product is animal component-free.

Supplier: Adipogen

BAFF is mainly produced by innate immune cells such as neutrophils, monocytes, macrophages, dendritic cells, follicular dendritic cells. T cells, activated B cells, some malignant B cells and also non-lymphoid cells like astrocytes, synoviocytes and epithelial cells can also produce BAFF. BAFF binds three distinct receptors (BAFF-R, TACI and BCMA) expressed predominantly on B cells, although activated T cells also express BAFF-R. BAFF is a master regulator of peripheral B cell survival, and together with IL-6, promotes Ig class-switching and plasma cell differentiation. Besides its major role in B cell biology, BAFF co-stimulates activated T cells. Deregulated expression of BAFF leads to autoimmune disorders in mice. In humans, elevated levels of soluble BAFF have been detected in the serum of patients with various autoimmune diseases such as Sjoegren syndrome, Rheumatoid arthritis (RA), Multiple sclerosis (MS) and Systemic Lupus Erythematosus (SLE). BAFF has also increased levels in some lymphoid cancers.

Supplier: BioVendor

Alpha 1-microglobulin (A1M) is a lipocalin superfamily member (kernal lipocalins). A1M is a low molecular weight protein component of plasma. A1M is distributed in plasma and extravascular compartments of all organs. Alpha-1 Microglobulin is found in mammals, birds, amphibians and fish. The primary sites of A1M synthesis are the liver and the kidney. Around the opening of the lipocalin pocket three lysyl residues are situated; those residues carry yellow-brown modification derived from the binding and degradation of heme and kynurenin (a tryptophan metabolite). A1-Microglobulin’s reductase and dehydrogenase have broad biological substrate specificity properties due to its’ free cysteine side-chain which is located in a flexible loop. Alpha-1-microglobulin is glycosylated by three separate carbohydrate chains: two complex carbohydrates which are N-linked to asparagines at residues 17 and 96, and the other simple carbohydrate which is O-linked to threonine at position 5. The carbohydrates comprise 22% of the total molecular mass of the protein. The glycosylation varies between species. A1M exists in two forms- a free form and complexed to other macromolecules: in humans- complexed to immunoglobulin A (IgA), in rat- complexed to alpha-1-inhibitor-3. Free A1M is exceptionally heterogeneous in charge (therefore also known as protein HC), and is found tightly linked to a chromophore. The free Alpha-1-microglobulin is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link. The chromophoric group is covalently bound to the free cysteine residue at position 34. A1M binds retinol as a major ligand, but this is probably distinct from its covalent chromophore.

Supplier: Stemcell Technologies

Interleukin 31 (IL-31), a four-helix bundle inflammatory cytokine, belongs to the IL-6 cytokine family which includes IL-6 (MSPP-78050), oncostatin M (MSPP-78094), leukemia inhibitory factor (LIF; MSPP-78055), and cardiotrophin-1 (Dillon et al.). IL-31 signals through a heterodimer composed of IL-31RA (also known as gp130-like receptor or GPL) and the oncostatin-M receptor (OSMR), both of which are expressed on monocytes (Diveu et al.; Ghilardi et al.), epithelial cells (Ip et al.), and keratinocytes (Kato et al.). Signaling through the GPL/OSMR complex activates the JAK/STAT, RAS/ERK, and PI3K/AKT signaling pathways, resulting in the downstream activation of STAT1, STAT3, and STAT5 transcription factors (Cornelissen et al.; Dambacher et al.; Dillon et al.; Ip et al.). IL-31 responses have been associated with allergic responses and inflammatory skin diseases including atopic dermatitis (Cornelissen et al.; Gangemi et al.).

Supplier: Stemcell Technologies

Betacellulin is a member of the epidermal growth factor (EGF) family, and signals through EGF receptor and ERBB4. It activates ERK and AKT pathways, which induces neural stem cell proliferation and prevents spontaneous differentiation in culture. Betacellulin stimulates the expansion of neural stem cells, transit-amplifying cells, and neuroblasts derived from subventricular zone and dentate gyrus (Gómez-Gaviro et al.). It is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells. Betacellulin down-regulates E-cadherin expression in ovarian cancer cell lines via MEK/ERK1/2 and PI3K/AKT signaling pathways, thus increasing cell migration (Zhao et al.). It is a modulator of interferon (IFN) response and enhances anti-viral effects of IFN (Al-Yahya et al.). Betacellulin is expressed in pancreatic α cells, β cells, and duct cells. It induces the proliferation of pancreatic cancer cell lines, inhibits apoptosis, promotes the neogenesis of β cells, and converts non-β cells into insulin-producing cells (Kawaguchi et al.; Miyagawa al.; Saito et al.).

Supplier: Advanced Biomatrix

Poly-L-Ornithine is a synthetic amino acid chain that is positively charged having one hydrobromide per unit of ornithine. Poly-L-Ornithine is widely used as a coating to enhance cell attachment and adhesion to both plasticware and glass surfaces.

The molecular weight of Poly-L-Ornithine can vary significantly with lower molecular weight (30,000 Da) being less viscous and higher molecular weight (>300,000 Da) having more binding sites per molecule. This product’s molecular weight ranges from 70,000 to 150,000 Da yielding a solution viscosity for easy handling while providing sufficient binding sites for cell attachment.

Poly-L-Ornithine surface coatings are designed to improve cell attachment, growth and differentiation of many cell types. Coated surfaces will often improve cell attachment in reduced or serum-free conditions. This product is supplied in a sterile 50 ml package size at a concentration of 0.1 mg/ml.

Supplier: Stemcell Technologies

Leukemia inhibitory factor (LIF) is an interleukin 6 class cytokine that regulates a broad variety of developmental functions. After LIF binds to LIF receptor (LIFR), LIFR associates with gp130 and activates JAK/STAT and MAPK signaling (Auernhammer and Melmed; Suman et al.). LIFR activation of STAT3 is essential for maintaining the mouse embryonic stem cell phenotype (Niwa et al.). Produced by the endometrium, LIF plays an important autocrine and paracrine role in implantation by regulating proliferation, invasion, and differentiation of trophoblasts following blastocyst attachment (Auernhammer and Melmed; Suman et al.). Human LIF can be used for the maintenance of mouse embryonic stem cells, however mouse LIF cannot bind to the human receptor, thus rendering mouse LIF inactive (Dahéron et al.). LIF is produced by CD4+ and activated regulatory T cells, and promotes Foxp3 expression, while repressing Th17 lineage-specific genes (Metcalfe). LIF is also secreted by mesenchymal stromal cells, where it supports hematopoiesis and immune modulation (Nasef et al.).

Supplier: Stemcell Technologies

Interferon-gamma (IFN-γ), also known as type II interferon, is produced by T and NK cells, and in smaller amounts by dendritic cells and macrophages. IFN-γ is controlled by cytokines such as IL-12 and IL-18 secreted in response to infection (Schroder et al.). IFN-γ binds to a receptor complex and initiates signal transduction via the JAK/STAT pathway; this culminates in the transcription and activation of many genes that control a diverse array of immunological functions (de Weerd and Nguyen; Krause et al.). IFN-γ stimulates the antimicrobial and anti-tumor activity of macrophages, NK cells, and neutrophils (Billiau and Matthys) by promoting the activation of microbial effector functions such as production of reactive oxygen species, NO intermediates, and complement (Schroder et al.). IFN-γ enhances MHC class I and II expression in dendritic cells and mononuclear phagocytes, as well as the production of IL-12 by dendritic cells. In B cells, IFN-γ stimulates survival and growth in both mouse and human cells, and redirects B cells from proliferation towards differentiation. IFN-γ favors the development of Th1 vs Th2 cells and stimulates monocyte differentiation and function (Schroder et al.). This product is animal component-free.

Supplier: Stemcell Technologies

Interleukin 11 (IL-11) is a pleiotropic cytokine with effects on various tissues including the bone marrow, brain, and intestinal mucosa (Du and amp; Williams). It belongs to the IL-6 family of cytokines that share a common signal transducer, gp130. Culture of mouse bone marrow cells with IL-11 in combination with IL-3, IL-6, and stem cell factor induces significant expansion and proliferation of colony-forming cells in vitro (Peters et al.). In addition, in combination with IL-3, IL-11 significantly enhances the growth of megakaryocytic colonies in vitro, suggesting its role in augmenting mouse megakaryopoiesis (Yonemura et al.). IL-11 is expressed in a wide range of normal adult mouse tissues, including the central nervous system, thymus, lung, and bone. The mouse IL-11 cDNA was cloned using an expression library generated from the lipopolysaccharide-induced mouse fetal thymic cell line, T2 (Morris et al.). The binding of IL-11 to its receptor induces heterodimerization with the gp130 subunit and activation of JAK tyrosine kinases. IL-11 also plays a role in cancer progression by inducing the proliferation of epithelial cancer cells and the survival of metastatic cells at distant organs. Recently, IL-11 has gained interest for its role in the pathogenesis of diseases in dysregulated mucosal homeostasis associated with STAT3 upregulation, including gastrointestinal cancers (Putoczki et al.).

Supplier: Advanced Biomatrix

VitroCol® collagen is the first widely available, naturally produced purified human collagen for research purposes. VitroCol® sets the standard for purity (>99% collagen content), functionality and represents the only native-like human collagen offered.

VitroCol® collagen is naturally secreted from human neo-natal fibroblast cells. The human fibroblasts are cultured in optimal conditions allowing the fibroblasts to naturally and efficiently secret extracellular matrix. The extracellular matrix is then processed and purified to yield the naturally produced human collagen.

VitroCol® is approximately 97% Type I human collagen with the remainder being comprised of Type III collagen. It contains high monomer content as measured by gel permeation chromatography.

This product is supplied as a lyophilized powder with 15 mg of human collagen. When reconstituted with 5 ml of sterile 0.01 N HCl, a concentration of approximately 3 mg/ml is achieved.

VitroCol® is especially ideal for human cell culture systems when coating of surfaces and providing preparations of thin layers of culturing cells. VitroCol®, lyophilized form is not recommend for the formation of a solid gel. VitroCol® human collagen is provided in user-friendly packaging for use and storage. VitroCol® is supplied as a sterile, lyophilized powder.

Supplier: Stemcell Technologies

Stem cell factor (SCF) is an early-acting cytokine that plays a pivotal role in the regulation of embryonic and adult hematopoiesis. SCF promotes cell survival, proliferation, differentiation, adhesion, and functional activation of cells at multiple levels of the hematopoietic hierarchy. Together with other cytokines such as thrombopoietin and Flt3/Flk-2 Ligand, SCF is commonly used to promote expansion of primitive hematopoietic stem cells and multi-potent progenitor cells in culture (Huang et al.; Kent et al.). In synergy with various growth factors, including IL-2, IL-3, IL-6, IL-7, G-CSF, and erythropoietin, SCF increases proliferation and differentiation of myeloid and erythroid progenitor cells and a subset of lymphoid progenitor cells (Broudy). In the mouse, SCF is essential during fetal gonadal development (Mauduit). It is produced by stromal cells in the fetal liver, bone marrow, and thymus, in the central nervous system, in keratinocytes, and in the gut mucosa, and can function as a chemotactic and chemokinetic factor. SCF exists in two biologically active splice forms: a soluble and a transmembrane isoform. Upon binding to its receptor (c-kit tyrosine kinase receptor; CD117), it activates PI3K, JAK/STAT, and MAPK pathways. SCF and signaling from c-kit has also been reported to play an important role in pigmentation, fertility, vasculogenesis, motility of the gut via c-kit-positive interstitial cells of Cajal, and in the migration of neuronal stem and progenitor cells to sites of injury in the brain (Lennartsson and Ronnstrand).

Supplier: AAT Bioquest

Z-VAD-CHO, also generically called as 'Caspase Inhibitor II', is a cell-permeable, reversible pan-caspase inhibitor, blocks all features of apoptosis in THP.1 and Jurkat T-cells.