Description
General description
Glucagon-like peptide-I (GLP-1), a member of the glucagon-secretin peptide family, is secreted from L-cells of the small intestine and binds to a class B (class 2) G protein-coupled receptor (Mayo et al. 2003). The GLP-1 receptor is expressed in pancreatic beta cells and upon binding to GLP-1, it couples to Gs to increase cAMP levels and insulin secretion (Drucker et al. 1987). In addition, GLP-1 has been shown to delay gastric emptying and regulate appetite. Therefore, the GLP-1 receptor represents an important therapeutic target for type II diabetes, and a degradation-resistant analog of GLP-1, exanatide, is used clinically in combination with other glucose-lowering drugs to control type II diabetes (D’Alessio et al. 2004). Millipore′s GLP-1 receptor 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 for agonists and antagonists at the GLP-1 receptor. The membrane preparations exhibit a Kd of 0.27 nM for [125I]-GLP-1. With 10 μg/well GLP-1 Receptor Membrane Prep and 0.5 nM [125I]-GLP-1, a greater than 9-fold signal-to-background ratio was obtained.
Human GLP-1
Application
Radioligand binding assay, and GTPγS binding.
Biochem/physiol Actions
GPCR Class: B
Protein Target: GLP-1
Target Sub-Family: Glucagon
Features and Benefits
Inucbation 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 50mM 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] GLP-1(7-36) (Perkin Elmer # NEX308)
Wash Buffer: 50 mM Hepes, pH 7.4, 500mM NaCl , 0.1% BSA, filtered and stored at 4°C.
Physical form
One package contains enough membranes for at least 200 assays (units), where an unit is the amount of membrane that will yield greater than 9-fold signal:background with 125I-labeled GLP-1 at 0.5 nM.
Liquid in packaging buffer: 50 mM Tris pH 7.4, 10% glycerol and 1% BSA with no preservatives.
Packaging method: Membranes protein were adjusted to the indicated concentration in packaging buffer, rapidly frozen, and stored at -80°C.
Preparation Note
Maintain frozen at -70°C for up to 2 years. Do not freeze and thaw.
Analysis Note
SPECIFICATIONS:
Signal:background and specific binding values obtained in a competition binding assay with varying amounts of GLP-1 membrane prep:
20 µg/well10 µg/well
Signal:Background 12.0 14.9
Specific Binding (cpm) 31366 27411
1 unit = 10 µg membrane preparation
Bmax: 3.96 pmol/mg
Kd: 0.27 nM
Legal Information
CHEMICON is a registered trademark of Merck KGaA, Darmstadt, Germany
Disclaimer
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.
