Identification of full, partial and inverse CC chemokine receptor 3 agonists using [35S]GTPγS binding
| Autor: | Shelby P. Umland, M. Motasim Billah, Yuntao Wan, Charles G. Garlisi, Fang Tian, Pauline C. Ting, Robert W. Egan, Hongchen Qiu, James Jakway, David Hesk, Himanshu Shah |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Chemokine CCL11
Agonist Eotaxin medicine.medical_specialty medicine.drug_class Receptors CCR3 GTPgammaS CHO Cells Biology Sulfur Radioisotopes Transfection Binding Competitive Partial agonist Cell Line Radioligand Assay chemistry.chemical_compound immune system diseases Cricetinae Internal medicine medicine Animals Humans Inverse agonist Binding site Receptor Chemokine CCL5 Cells Cultured Pharmacology Dose-Response Relationship Drug Cell Membrane hemic and immune systems Molecular biology Monocyte Chemoattractant Proteins Rats Eosinophils Endocrinology chemistry Guanosine 5'-O-(3-Thiotriphosphate) Chemokines CC Receptors Chemokine Chemokines CC chemokine receptors |
| Zdroj: | European Journal of Pharmacology. 456:1-10 |
| ISSN: | 0014-2999 |
| DOI: | 10.1016/s0014-2999(02)02621-3 |
| Popis: | Study of the CC chemokine receptor 3 (CCR3) has been limited to using radiolabeled agonist chemokines. A small molecule CCR3 antagonist, 2-[(6-amino-2-benzothiazolyl)thio]-N-[1-[(3,4-dichlorylphenyl)methyl]-4-piperidinyl]acetamide, Banyu (I), was tritiated and used for pharmacological studies. Banyu (I) has a K(d) of 5.0+/-0.4 and 4.3+/-1.8 nM on human CCR3 transfectants and eosinophils, and noncompetitively inhibits [125I]eotaxin binding and eotaxin-induced [35S]guanosine-5'-O-(3-thiotriphosphate) ([35S]GTPgammaS) binding. The proportion of [125I]eotaxin: [3H]Banyu (I) binding sites in eosinophils or transfectants was 35% or 13%, although both binding sites were overexpressed in transfectants. CCR3 spontaneously couples to G-proteins in CCR3 transfectants, demonstrated by changes in basal and eotaxin-induced [35S]GTPgammaS binding under reduced NaCl and GDP concentrations. Consequently, Banyu (I) was identified as an inverse agonist. In contrast, CCL18 and I-TAC (interferon-inducible T cell alpha-chemoattractant) were neutral antagonists, inhibiting eotaxin-induced [35S]GTPgammaS binding, with minimal effect on basal coupling of CCR3 to G proteins. Eotaxin, eotaxin-2 and monocyte chemoattractant protein (MCP)-4 are full agonists inducing [35S]GTPgammaS binding; eotaxin-3, MCP-3, RANTES (regulated on activation normal T cell expressed and secreted), vMIP-I (Kaposi's sarcoma-associated herpesvirus macrophage inflammatory protein-) and vMIP-II are partial agonists, indicating that this is a sensitive method to quantitate agonist efficacy. |
| Databáze: | OpenAIRE |
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