Key Specifications Table
| Species | Host Cells | Protein Target |
|---|---|---|
| Human | Chem-1 | CXCR4 |
| Description | |
|---|---|
| Catalogue Number | HTS004M |
| Brand Family | Chemicon® |
| Trade Name |
|
| Description | ChemiSCREEN™ CXCR4 Membrane Preparation |
| Overview | Full-length human CXCR4 cDNA |
| Background Information | The chemokine SDF-1a and its GPCR receptor CXCR4 have a one-to-one specificity that is unique among chemokines and their receptors. SDF-1a binds to CXCR4 expressed on hematopoietic and lymphopoietic cells, and directs their trafficking to and retention in hemato-and lymphatopoietic organs and sites of inflammation (Kucia et al., 2004). CXCR4 is expressed on several tumor cell lineages, and might be responsible for metastasis to sites of SDF-1a expression, such as bone and lymph nodes (Muller et al., 2001). In addition, CXCR4 is a coreceptor for the HIV envelope glycoprotein gp120 (Feng et al., 1996). Small molecule antagonists of CXCR4 have been developed and shown to inhibit infectivity of T-tropic HIV strains and to impair growth of brain tumors (Arakaki et al., 1999; Rubin et al., 2003). Chemicons CXCR4 membrane preparations are crude membrane preparations made from our proprietary stable recombinant cell lines to ensure high-level of GPCR surface expression; thus, they are ideal tools for screening for antagonists of interactions between CXCR4 and SDF-1a. Radiolabeled SDF-1a binds to the CXCR4 membranes with a Kd of 0.9 nM. With 0.04-0.13 nM 125I-labeled SDF-1a, an approximately 3-fold window of specific binding is obtained. |
| Product Information | |
|---|---|
| Format | Membranes |
| Presentation | Packaging buffer: 50 mM Tris pH 7.4, 10% glycerol and 1% BSA Packaging method: Membranes protein were adjusted to 0.5 mg/ml in 1 ml packaging buffer, rapidly frozen, and stored at -80°C. |
| Quality Level | MQ100 |
| Applications | |
|---|---|
| Application | Human CXCR4 GPCR membrane preparation for Radioligand binding Assays & GTPgammaS binding. |
| Key Applications |
|
| Application Notes | Radioligand binding assay and GTPgammaS binding. |
| Biological Information | |
|---|---|
| Concentration | 2 mL, 0.5 mg/mL |
| Entrez Gene Number |
|
| Entrez Gene Summary | This gene encodes a CXC chemokine receptor specific for stromal cell-derived factor-1. The protein has 7 transmembrane regions and is located on the cell surface. It acts with the CD4 protein to support HIV entry into cells and is also highly expressed in breast cancer cells. Mutations in this gene have been associated with WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. |
| Gene Symbol |
|
| GPCR Class | A |
| Host Cells | Chem-1 |
| Protein Target | CXCR4 |
| Target Sub-Family | Chemokine |
| UniProt Number |
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| UniProt Summary | FUNCTION: SwissProt: P61073 # Receptor for the C-X-C chemokine CXCL12/SDF-1. Transduces a signal by increasing the intracellular calcium ions level. Involved in haematopoiesis and in cardiac ventricular septum formation. Plays also an essential role in vascularization of the gastrointestinal tract, probably by regulating vascular branching and/or remodeling processes in endothelial cells. Could be involved in cerebellar development. In the CNS, could mediate hippocampal-neuron survival. Acts as a coreceptor (CD4 being the primary receptor) for HIV-1 X4 isolates and as a primary receptor for some HIV-2 isolates. Promotes Env-mediated fusion of the virus. SIZE: 352 amino acids; 39746 Da SUBUNIT: Interacts with HIV-1 surface protein gp120 and Tat. SUBCELLULAR LOCATION: Cell membrane; Multi-pass membrane protein. TISSUE SPECIFICITY: Expressed in numerous tissues, such as peripheral blood leukocytes, spleen, thymus, spinal cord, heart, placenta, lung, liver, skeletal muscle, kidney, pancreas, cerebellum, cerebral cortex and medulla (in microglia as well as in astrocytes), brain microvascular, coronary artery and umbilical cord endothelial cells. Isoform 1 is predominant in all tissues tested. DOMAIN: SwissProt: P61073 The amino-terminus is critical for ligand binding. Residues in all four extracellular regions contribute to HIV-1 coreceptor activity. PTM: Sulfated. DISEASE: SwissProt: P61073 # Defects in CXCR4 are a cause of WHIM syndrome [MIM:193670]; also called warts, hypogammaglobulinemia, infections, and myelokathexis. WHIM syndrome is an immunodeficiency disease characterized by neutropenia, hypogammaglobulinemia and extensive human papillomavirus (HPV) infection. Despite the peripheral neutropenia, bone marrow aspirates from affected individuals contain abundant mature myeloid cells, a condition termed myelokathexis. SIMILARITY: Belongs to the G-protein coupled receptor 1 family. |
| Incubation Conditions | RECOMMENDED ASSAY CONDITIONS: Membranes are mixed with radioactive ligand and unlabeled competitor (see Figures 1 and 2 for concentrations tested) in binding buffer in a nonbinding 96-well plate, and incubated for 1-2 h. Prior to filtration, a GF/C 96-well filter plate is coated with 0.33% polyethyleneimine for 30 min, then washed with 50 mM HEPES, pH 7.4, 0.5% BSA. Binding reaction is transferred to the filter plate, and washed 3 times (1 mL per well per wash) with Wash Buffer. The plate is dried and counted. Binding buffer: 50 mM Hepes, pH 7.4, 5 mM MgCl2, 1 mM CaCl2, 0.2% BSA, filtered and stored at 4°C Radioligand: [125I] SDF-1alpha (PerkinElmer#: NEX346) Wash Buffer: 50 mM Hepes, pH 7.4, 500 mM NaCl , 0.1% BSA, filtered and stored at 4°C. One vial contains enough membranes for at least 200 assays (units), where an unit is the amount of membrane that will yield greater than 4-fold signal:background with 125I-labeled SDF-1alpha at 0.13 nM. |
Table 1. Signal:background and specific binding values obtained in a competition binding assay with CXCR4 membrane prep, 0.13 nM 125I-SDF-1α and a dilution series of unlabeled SDF-1α.
| Product Usage Statements |
|---|
| 5 µg/well | |
|---|---|
| Signal:Background | 4.9 |
| Specific Binding (cpm) | 9004 |
Specifications:
1 unit = 5 μg
Bmax [125I]-SDF-1alpha binding: 1.6 pmol/mg protein
Kd for [125I] SDF-1alpha binding: ~ 0.9 nM Usage Statement
- Unless otherwise stated in our catalog or other company documentation accompanying the product(s), our products are intended for research use only and are not to be used for any other purpose, which includes but is not limited to, unauthorized commercial uses, in vitro diagnostic uses, ex vivo or in vivo therapeutic uses or any type of consumption or application to humans or animals.
| Storage and Shipping Information | |
|---|---|
| Storage Conditions | Maintain frozen at -70°C for up to 2 years. Do not freeze and thaw. |
| Packaging Information | |
|---|---|
| Material Size | 200 units |