Overcome the Challenges of Hit Identification for Molecular Glues
Typically, the identification of molecular glues has been limited by a lack of effective hit identification strategies, with many traditional assay methodologies facing challenges when applied to molecular glue targets. To overcome this limitation, Charles River offers a reliable suite of hit identification and validation screening strategies, including a high-throughput ASMS assay to screen for molecular glues against any target.
The use of molecular glues is a rapidly flourishing area within drug discovery that can allow access to otherwise undruggable targets. Molecular glues can bring two proteins into proximity and better stabilize naturally occurring protein-protein interactions. We have the experience and expertise to help you find and progress your candidate from hit to clinical development.
Molecular Glue Screening Approaches
Charles River’s unique molecular glue screening offers innovative solutions for identifying molecular glue hit compounds in a high-throughput and reliable manner. Our experienced hit identification team will work with you to identify and design a screening approach to produce hits that will support your strategy and research goals.
Molecular Glue Degrader Screening Collection
You are invited to screen against your own compound library or take advantage of our >1.3 M diverse compound collection, with optional CADD refinement. For molecular glue degrader programs, screens can be supplemented with our molecular glue degrader collection, incorporating a bespoke set of molecular glue-like compounds.
Structural motifs that comprise the Charles River molecular glue degrader screening collection.
Our customized collection is based on well-characterized, high-confidence molecular glue degrader structural motifs which have been assessed pre-clinically and in clinical evaluation.
Molecular Glue Screening Assays
SAMDI ASMS
The SAMDI (Self-Assembled Monolayer Desorption Ionization) affinity selection mass spectrometry (ASMS) technology is a high-throughput label-free assay that can be used to accelerate your molecular glue hit identification and inform on potency and selectivity. This multi-modality innovative approach is used to identify small molecules that bind to virtually any target, including complexes. Compared to traditional ASMS approaches, SAMDI ASMS offers a faster workflow and readout, target consumption savings up to 50-fold, minimization of compound misbehavior, and features a screening capacity of hundreds of thousands of compounds in days.
To identify candidate molecular glues using SAMDI ASMS, each compound is incubated with the individual proteins and complex in separate channels in parallel. Compounds that generate a preferential signal for the complex relative to the individual proteins are selected for further investigation of molecular glue behavior.
DEL Screening
DNA-encoded library (DEL) screening at Charles River is an ultra-high throughput hit identification method, where enormous chemical space (>11 billion compounds) can be screened in a single experiment. This affinity-based approach can be used to identify molecular glues by screening for binary and ternary complexes in parallel, and subsequently computationally deconvoluting the output to highlight molecular glue binders. By screening multiple targets or conditions in parallel, DEL screening can also inform on molecular glue selectivity.
Our DEL screening service is a fully inclusive package, designed to significantly maximize your success rate by taking advantage of our experienced DEL team during the curation and study design phase, and incorporating DEL-focused protein production and quality control.
Surface Plasmon Resonance (SPR)
Surface Plasmon Resonance (SPR) is an ideal follow-on study to SAMDI ASMS screening for molecular glues and can be employed to study molecular interactions, kinetics, and mode-of-action using the following workflow:
- Immobilization: Attach one of the interacting molecules (possibly the molecular glue) onto the SPR sensor surface, using appropriate controls and validate results to ensure the reliability of the data obtained.
- Concentration Studies: Investigate how changes in analyte concentration affect binding, providing insights into the binding affinity and stoichiometry.
- Kinetic Analysis: SPR allows the determination of association and dissociation rates, equilibrium constants, and binding kinetics. This information can elucidate the strength and dynamics of molecular interactions involving the glue.
- Detection: Monitor changes in the SPR signal as the molecules interact. Binding events cause alterations in refractive index at the sensor surface, leading to shifts in resonance angle.
- Flowing Analyte: Introduce the other binding partner (e.g., another molecule or surface) as the analyte in solution over the immobilized surface.
Once hits are identified, Charles River’s portfolio of biochemical, biophysical, and cellular assays can be used to validate your molecular glue candidates and demonstrate efficacy in relevant models. We provide a broad selection of orthogonal assays for follow-on validation of hits. Your Hit ID team will work with you to identify the technologies and methodologies best suited to validate your hit matter and assist you with program design.
Frequently Asked Questions (FAQs) About Molecular Glues
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What is a molecular glue and what are they used for?
A molecular glue is a small molecule that adheres two or more proteins together. In some cases, the proteins may not naturally interact while in other cases the glue stabilizes a naturally occurring protein-protein interaction, resulting in a therapeutic effect. Two similar modes have been described: A small molecule may bind to a first protein, creating a neosubstrate for a second protein to interact with the small molecule-protein complex. In a second example, a small molecule binds to a neosubstrate presented when two or more proteins form a complex.
In a classical example, a molecular glue induces the proximity of a protein of interest (POI) and an E3-ligase that results in the ubiquitination of the POI and its subsequent degradation through the proteosome. However, other strategies aim to modify the POI with post-translational modifications (e.g. phosphorylation, acetylation, methylation, or to remove a ubiquitin and prevent its degradation, and stabilize a complex).
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What are the advantages of a molecular glue compared to other modalities?
Compared with other proximity modalities such as proteolysis-targeting chimeras, a molecular glue is a small molecule that often features many of the desirable properties of a therapeutic drug, such as "Lipinski’s rule of 5," and crosses biological borders such as membranes and the blood-brain barrier.
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What are the advantages of molecular glue degraders?
Molecular glue molecules stabilize, or enhance, protein-protein interactions to control biological functions, allowing access to otherwise undruggable targets. Moreover, molecular glues have received significant attention in the field of proteosome-based targeted protein degradation, as molecular glue degraders typically have reduced molecular weight, lower structural complexity, and are more drug-like compared to heterobifunctional proteolysis-targeting chimeras.