PROTAC and RIPTAC Binding Research

PROTAC and RIPTAC Binding Research (Learn More about Ubiquitination)

PROTAC (Proteolysis Targeting Chimera) is a targeted protein degradation technology. It induces the formation of a ternary complex between the protein of interest and E3 ubiquitin ligase, thereby promoting ubiquitination and subsequent degradation of the target protein. Unlike conventional inhibitors, which mainly focus on compound binding to a single target, PROTAC research places critical emphasis on assessing the capacity to form the Target Protein–PROTAC–E3 Ligase ternary complex. This represents an essential step for evaluating the activity of candidate PROTAC molecules.

Principle of PROTAC-Mediated Targeted Protein Degradation. PROTAC molecules simultaneously engage a target protein and an E3 ubiquitin ligase to promote formation of a ternary complex. This complex facilitates target protein ubiquitination and subsequent proteasomal degradation. Assessment of ternary complex formation provides an important molecular readout for evaluating candidate PROTAC activity and supporting targeted protein degradation research.

KeyTec® TR-FRET leverages the property of proximity-dependent energy transfer between Donor and Acceptor to detect PROTAC-mediated protein complex formation. When Target Protein, PROTAC and E3 Ligase assemble into a stable ternary complex, the Donor and Acceptor conjugated to the detection molecules are brought into close proximity, generating measurable TR-FRET signals. By comparing signal variations across different compounds and concentrations, the ability of PROTAC molecules to promote ternary complex formation can be evaluated.

1 PROTAC Ternary Complex Detection

PROTAC characterization can be performed at multiple levels, including E3 Ligase binding, target protein binding and ternary complex formation. We supply the Human Cereblon Binding Kit and Human VHL Binding Kit for CRBN- and VHL-related binding studies, providing assay tools to set up different E3 Ligase recruitment systems.

For ternary complex research, we further offer TR-FRET assay products for various Target Protein/E3 Ligase combinations, including STAT6/CRBN, BTK-WT/CRBN, BRD4/VHL, ALK/CRBN and NEK7/CRBN. These kits support studies on PROTAC-induced complex formation across diverse target–E3 ligase pairs.

2 From E3 Ligase Binding to Ternary Complex Characterization

PROTAC efficacy depends not only on its individual binding to Target Protein or E3 Ligase, but also strongly correlates with ternary complex assembly. TR-FRET detection of these binding events enables researchers to assess candidate molecules at multiple mechanistic layers.

By testing a series of PROTAC concentrations, researchers can compare binding and ternary complex formation responses among different candidate molecules and further analyze concentration-dependent effects. This assay strategy supports PROTAC candidate screening, molecular comparison and assessment of ternary complex formation capacity, providing experimental evidence at the binding level for subsequent protein degradation mechanism studies.

3 RIPTAC Ternary Complex Research

In addition to conventional PROTACs, RIPTAC (Reversible Induced Proximity Targeting Chimera) also relies on induced proximity between proteins to exert specific biological effects. Evaluation of protein complex formation is therefore essential during RIPTAC characterization.

For RIPTAC research, we provide the BRD4/AR RIPTAC Binding Assay Kit for binding analysis of RIPTAC-mediated ternary complex formation between BRD4 and AR. It can be applied to binding studies and mechanism-of-action evaluation of candidate RIPTAC molecules.

4 For Targeted Protein Degradation and Induced Proximity Research

KeyTec® TR-FRET PROTAC/RIPTAC products cover E3 Ligase binding, Target Protein/E3 Ligase ternary complex formation and specific RIPTAC binding systems, meeting diverse experimental requirements ranging from basic binding assays to candidate molecule screening.

Related products can be applied to:

- E3 Ligase binding research: Binding analysis for E3 ligases such as CRBN and VHL;

- PROTAC ternary complex research: Assessment of complex formation across various Target Protein/E3 Ligase combinations;

- Candidate molecule screening: Comparison of binding responses under different compounds and concentration conditions;

- Mechanism-of-action research: Analysis of the capacity of PROTAC/RIPTAC to induce protein proximity at the binding level;

- Targeted protein degradation drug discovery: Supply assay tools for early evaluation and optimization of candidate molecules.

5 KeyTec® PROTAC & RIPTAC Assay Product Portfolio

6 Advantages of KeyTec® TR-FRET PROTAC/RIPTAC Assays

- Focused on Ternary Complex Formation: Assays detect PROTAC/RIPTAC-induced protein proximity and complex assembly, closely supporting molecular mechanism studies.

- Coverage of Major E3 Ligases: CRBN and VHL binding and ternary complex assay systems are available to support research into diverse E3 ligase recruitment strategies.

- Diverse Target Combinations: Covers multiple targets including STAT6, BTK, BRD4, ALK and NEK7, offering assay options for evaluating various candidate molecules.

- Candidate Molecule Screening Enabled: TR-FRET signal changes measured across compounds and concentrations allow comparison of binding responses for candidate PROTAC/RIPTAC molecules.

Centered on protein proximity and ternary complex formation, KeyTec® TR-FRET PROTAC/RIPTAC Assays deliver professional assay products and solutions for E3 Ligase binding studies, PROTAC/RIPTAC ternary complex analysis, candidate screening and mechanism-of-action research.

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