ChemiSCREEN Membrane Preparation Recombinant Human 5-HT_4B Serotonin Receptor

Inucbation Conditions
RECOMMENDED ASSAY CONDITIONS: Membranes are mixed with radioactive ligand and unlabeled competitor (see Figures 1 and 2 for concentrations tested) in assay buffer in a nonbinding 96-well plate, and incubated for 1-2 h. Prior to filtration, an FC 96-well harvest plate (Millipore cat. # MAHF C1H) is coated with 0.33% polyethyleneimine for 30 min, then washed with assay buffer. Binding reaction is transferred to the filter plate, and washed 3 times (1 mL per well per wash) with assay buffer. The plate is dried and counted.

Assay buffer: 25 mM Tris, pH 7.4, filtered and stored at 4°C

Radioligand: [³H]-GR113808 (Amersham TRK944)

One package contains enough membranes for at least 200 assays (units), where one unit is the amount of membrane that will yield greater than 10-fold signal:background with ³H-labeled GR113808 at 1 nM.

Table 1. Signal:background and specific binding values obtained in a competition binding assay with varying amounts of 5-HT_4B membrane prep.

	10 µg/well	5 µg/well
Signal:Background	26.4	21.7
Specific Binding (cpm)	5286	4879

SPECIFICATIONS: 1 unit = 5 μg membrane preparation
Bmax: 12.5 pmol/mg
K_d: 2.7 nM for [³H]-GR113808

Human 5-HT4 GPCR membrane preparation for Radioligand binding Assays & GTPγS binding.

Radioligand binding assay and GTPγS binding.

GPCR Class: A

Protein Target: 5-HT4

Target Sub-Family: Serotonin

RESEARCH USE ONLY. This product is regulated in France when intended to be used for scientific purposes, including for import and export activities (Article L 1211-1 paragraph 2 of the Public Health Code). The purchaser (i.e. enduser) is required to obtain an import authorization from the France Ministry of Research referred in the Article L1245-5-1 II. of Public Health Code. By ordering this product, you are confirming that you have obtained the proper import authorization.

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.

5-Hydroxytryptamine (5-HT, also commonly known as serotonin) is synthesized in enterochromaffin cells in the intestine and in serotonergic nerve terminals. In the periphery, 5-HT mediates gastrointestinal motility, platelet aggregation, and contraction of blood vessels. Many functions of the central nervous system are influenced by 5-HT, including sleep, motor activity, sensory perception, arousal and appetite. A family of 12 GPCRs and one ion channel mediate the biological effects of 5-HT (Hoyer et al., 1994). 5-HT₄ comprises at least 8 isoforms varying at the C-terminus, which are generated by alternative splicing. The expression and distribution of these splice variants differs among organs and tissues with many of them present in several tissues such as atrium, brain, and GI tract (Bockaert et al. 2004). To date, all isoforms have been shown to activate adenylyl cyclase in vitro, and no difference in signal transduction between C-terminal 5-HT₄ receptor variants has been demonstrated. 5-HT₄ receptors are of potential interest for the treatment of patients with GI motility disorders and Alzheimer′s disease (De Maeyer et al. 2008; Lezoualc’h 2007). Millipore′s 5-HT_4B 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 HTS tools for screening of agonists and antagonists of 5-HT_4B. The membrane preparations exhibit a Kd of 0.46 nM for [³H]-GR113808. With 1 nM [³H]-GR113808, 5 μg/well 5-HT4B Membrane Prep yields greater than 10 fold signal-to-background ratio.

Human HTR4, transcript b, encoding 5-HT_4B

Liquid in packaging buffer: 50 mM Tris pH 7.4, 10% glycerol and 1% BSA with no preservatives.
Packaging method: Membrane protein was adjusted to the indicated concentration in packaging buffer, rapidly frozen, and stored at -80°C.

Store at –70°C. Product is stable for at least 6 months from the date of receipt when stored as directed. Do not freeze and thaw.

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