SIAT^® Competition Binding Assay Service

Background Service Highlight Published Data FAQ Resources

Competitive binding assays, two (or more) ligands bind to the same receptor, are very important for biotherapeutic drug discovery. Relying on the state-of-art technology platform and profound expertise, Creative Biolabs offers a comprehensive range of competitive binding assay services to accelerate the customer's drug discovery process.

Competition Binding Assay

Ligand-receptor binding interactions are critical for biomedical research and drug discovery. Competitive binding assays are commonly used to measure the binding affinity of a ligand to its receptor. In this assay, the binding of a ligand labeled with a fluorescent or a radioactive tag is typically measured at a single concentration in the presence of different concentrations of an unlabeled, competing ligand. In order to measure binding affinity more accurately, a single binding protein is usually used in the assay. Either way, the competitive binding assay offers informative data to help guide your discovery program.

Our Service of Competition Binding Assay

Creative Biolabs' immunologic analysis experts have abundant experience in developing a wide range of competition binding assay in a variety of formats, ensuring your project has the custom assay solution you need. We provide high-quality competition binding assay services, including but not limited to:

Radiolabelling binding assay

Radiolabelling binding assays are widely used to measure the binding of drugs to their targets (enzyme, receptor, etc.), especially when the native ligands are difficult to label by other means, such as fluorescence. This binding assay has many advantages, including high affinity, low non-specific binding, high specific activity to detect low receptor densities, and high receptor specificity. Using the competition binding format, we can determine the affinity of unlabeled compounds at equilibrium. Radiolabelling binding assays also enable us to explore the binding mechanism of drug molecules and determine the binding kinetics by performing time-course testing.

Fluorescence-based assay

Fluorescence-based technologies are very important in pharmacological screening assays because they are amenable to miniaturization, and provide high sensitivity and signal-to-noise ratio.

1) Fluorescence polarization (FP)

Fluorescence polarization FP is a robust and sensitive technique for measuring the binding between two molecules in solution. This method uses polarized light to excite the ligand and measures the amount of light emitted. Depolarization of the emitted light depends on ligand being bound (e.g., to the receptor). If the ligand is not bound, it will have a large depolarization (ligand is free to spin rapidly, rotating the light). If the ligand is bound, the combined larger size results in slower rotation and therefore reduces the degree of depolarization, which allows measurement of the interaction and the effect of small molecule inhibitors on this.

2) Fluorescence resonance energy transfer (FRET)

Fluorescence resonance energy transfer FRET is a valuable tool for studying molecular interactions within and between biomolecules and is being used more and more in biomedical research and drug discovery today. FRET relies on the distance-dependent transfer of energy from the donor molecule to the acceptor molecule. Like FP, FRET uses a fluorescently labeled ligand. Many FRET assays use variants of the green fluorescent protein (GFP) in both in vitro and in vivo applications. The dipole-dipole interaction between the donor and the acceptor molecule transfers the energy from the donor to the acceptor molecule. If the ligand binds to the receptor-antibody complex, then the acceptor will emit light.

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High specificity, high sensitivity
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Creative Biolabs's technical experts will help you choose the best service to meet your specific needs. For more details on how we can provide innovative support to your project, please feel free to contact us.

Published Data

Binding Affinity Measurement of Molecules to Neuromelanin Using Fluorescence-based Assay

Fig. 1 Fluorescence of synthetic neuromelanin upon exposure to dopamine in the absence and presence of nicotine as a signal molecule. (Jackson Fink, 2019)

The article focuses on developing a competitive binding assay to measure the binding affinity of molecules to neuromelanin using fluorescence spectroscopy. This research is significant as it explores neuromelanin's role in neurodegeneration, specifically Parkinson's disease, by understanding how various compounds interact with it. The results demonstrated that neuromelanin has saturable binding interactions with nicotine, which was used to facilitate the competitive binding assay with other molecules that do not produce a signal themselves. This assay determined the dissociation constants for interactions with substances like methyl-phenyl-pyridinium ion (MPP+), dopamine, and 6-hydroxydopamine, which are central to understanding Parkinson's pathology.

Reference

Fink, Jackson, et al. "Development of a competition-binding assay to determine binding affinity of molecules to neuromelanin via fluorescence spectroscopy." Biomolecules 9.5 (2019): 175.

FAQ

What is a competitive binding assay and how is it used in biotherapeutic drug discovery?
A competitive binding assay is a biochemical technique used to measure the binding affinity and specificity of a ligand to a target molecule, often a receptor or enzyme. In biotherapeutic drug discovery, this assay helps identify and characterize potential drugs that can effectively compete with natural ligands for binding sites, indicating their therapeutic potential.
Why are competitive binding assays critical for evaluating the efficacy of biotherapeutics?
Competitive binding assays are crucial because they provide quantitative data on how well a biotherapeutic can displace a natural ligand from its binding site on a target protein. This information is vital for assessing the therapeutic's potential efficacy in modulating a biological pathway or disease state, allowing researchers to prioritize compounds with the best binding characteristics for further development.
How does the throughput of competitive binding assays impact drug discovery timelines?
High-throughput competitive binding assays enable the rapid screening of large libraries of potential therapeutics. By quickly identifying compounds that demonstrate effective binding, these assays accelerate the early stages of drug discovery, reducing the time and resources needed to identify promising candidates for more detailed evaluation.
What are the limitations of competitive binding assays in biotherapeutic development?
They typically do not provide information about the biological activity or downstream effects of the compound. Therefore, positive results in these assays must be complemented with further functional assays to assess the therapeutic efficacy and potential side effects in biological systems.
How do competitive binding assays differ from non-competitive binding assays in their application to drug discovery?
Competitive binding assays involve the competition between a test compound and a known ligand for the same binding site on a target molecule, which is crucial for determining the affinity and specificity of the test compound. In contrast, non-competitive binding assays measure the binding of a ligand to a site different from that of the test compound, providing information on potential allosteric modulators. Both assays are used to identify different interaction dynamics that are pivotal for drug efficacy and safety.
What role do competitive binding assays play in the optimization of biotherapeutics?
Competitive binding assays are integral in the iterative process of optimizing biotherapeutics. By repeatedly assessing how modifications to a biotherapeutic affect its binding to the target, researchers can refine the molecule for enhanced efficacy, reduced off-target effects, and improved pharmacokinetics. These assays are critical in fine-tuning the therapeutic prior to clinical development.
How are the results of competitive binding assays integrated into the larger drug discovery pipeline?
The results from competitive binding assays provide essential early-stage information that helps in the prioritization of compounds for further development. Successful candidates are typically advanced to more complex biological assays, such as cell-based assays and in vivo studies, to evaluate their functional efficacy and safety profile. This integration ensures that only the most promising compounds are developed further, optimizing resource allocation and strategic planning in drug discovery programs.