BB1 Membrane Preparation

Application

Radioligand binding assay, and GTPγS binding.

Biochem/physiol Actions

Target Sub-Family: Bombesin

Protein Target: BB1

GPCR Class: A

Disclaimer

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.

General description

Bombesin, a bioactive peptide first identified in amphibian skin, is related to two mammalian peptides, gastrin-releasing peptide (GRP) and neuromedin B (NMB). A family of 3 GPCRs, including NMB-R (BB₁), GRP-R (BB₂), and BRS-3 (BB₃), mediate the biological effects of the peptides. The receptors differ in their affinities for the peptides; BB2 binds to GRP with 50-300-fold greater affinity than to NMB, whereas BB1 binds to NMB with 10-800-fold greater affinity than to GRP (Tokita et al., 2004). Binding of ligand to BB1 activates Gq to increase intracellular calcium concentrations. The CNS is a major site of NMB and BB1 expression, and BB₁ appears to be involved in thermoregulation (Ohki-Hamazaki et al., 2005). Chemicon′s BB₁ 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 antagonists of BB1 interactions with neuromedin B. The membrane preparations exhibit a Kd of 0.35-0.43 nM for [¹²⁵I]-Bombesin. With 5 µg/well BB₁ Membrane Prep and 0.3 nM [¹²⁵I]-bombesin, a greater than 40-fold signal-to-background ratio was obtained.

Full-length human NMBR cDNA encoding BB1

Legal Information

CHEMICON is a registered trademark of Merck KGaA, Darmstadt, Germany

Packaging

1 mL per vial

200 units in 1 mL per vial

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 40-fold signal:background with ¹²⁵I-labeled bombesin at 0.3 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.

Quality

Signal:background and specific binding values obtained in a competition binding assay with varying amounts of BB₁ membrane prep:

Specifications

Inucbation ConditionsMembranes 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] bombesin (Perkin Elmer # NEX258)
Wash Buffer: 50 mM Hepes, pH 7.4, 500mM NaCl , 0.1% BSA, filtered and stored at 4°C.

Storage and Stability

Maintain frozen at -70°C for up to 2 years. Do not freeze and thaw.