TET Dioxygenase Activity Assay Service

CD BioSciences offers comprehensive TET dioxygenase activity assay services to characterize the enzymatic activities of TET family enzymes (TET1, TET2, TET3) responsible for active DNA demethylation through iterative oxidation of 5-methylcytosine. Our specialized platform enables accurate profiling of TET-mediated oxidation pathways, providing critical insights into epigenetic regulation mechanisms for basic research and therapeutic development.

Introduction to TET Dioxygenase

TET (ten-eleven translocation) dioxygenases are pivotal epigenetic erasers that catalyze the iterative oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) in an α-ketoglutarate- and Fe(II)-dependent manner. This oxidative demethylation pathway represents a crucial active DNA demethylation mechanism, dynamically regulating gene expression patterns during development and cellular differentiation. TET-mediated oxidation products serve not only as demethylation intermediates but also as stable epigenetic marks with distinct regulatory functions, influencing chromatin accessibility and transcription factor binding.

Fig.1 Domain structure of TET proteins. (An J, et al., 2017)

The three TET family members (TET1, TET2, TET3) exhibit both overlapping and specialized functions in maintaining epigenetic homeostasis. TET1 primarily regulates pluripotency in embryonic stem cells, TET2 functions as a key tumor suppressor in hematopoietic lineages, while TET3 plays essential roles in neuronal development. Beyond their developmental significance, TET dysregulation is implicated in various pathologies, including hematological malignancies, neurological disorders, and cardiovascular diseases. TET2 mutations are particularly prevalent in myelodysplastic syndromes and acute myeloid leukemia, establishing TET enzymes as critical biomarkers and therapeutic targets.

Our Services

CD BioSciences's technical approach is built upon a multi-platform detection strategy, integrating LC-MS/MS, fluorescence-based assays, and radioisotopic methods to provide a complete kinetic and quantitative profile of TET-mediated oxidation. We specialize in custom substrate design, optimized sample processing for labile modifications, and rigorous, controlled experimentation to ensure data accurately reflects specific enzymatic activity and biological context.

Mass Spectrometry-Based Quantification

Our LC-MS/MS platform simultaneously detects all TET oxidation products—5mC, 5hmC, 5fC, and 5caC—with femtomole-level sensitivity, providing absolute quantification and site-specific resolution for comprehensive pathway analysis.

Fluorescence Activity Assays

We enable real-time, homogeneous kinetic monitoring of TET enzyme activity. This method is ideal for high-throughput screening in 384-well formats, offering excellent signal-to-noise ratios for efficient compound evaluation.

Radioisotopic Detection Methods

We employ ³H-labeled methylated DNA substrates for direct and quantitative tracking of product formation. This established method provides a robust and linear measurement of enzymatic turnover, serving as a gold-standard validation tool.

Enzymatic Activity Profiling

We determine key kinetic parameters (Km, Vmax) and inhibitor constants (IC50, Ki) using purified systems. This detailed characterization is essential for understanding enzyme mechanism and supporting targeted drug discovery efforts.

Assay Strategy and Experimental Design

TET activity is evaluated by incubating defined DNA substrates containing 5mC with TET enzymes under optimized reaction conditions. Assay design focuses on controlling oxidation chemistry rather than methyl group transfer.

1. Key design considerations include:
2. DNA substrate length and modification state
3. Controlled Fe²+ and α-KG concentrations
4. Reducing environment optimization
5. Reaction timing to capture intermediate products

This design allows resolution of both overall dioxygenase activity and product-specific conversion efficiency.

Service Workflow

Our project execution follows a streamlined, collaborative five-phase workflow designed for transparency, efficiency, and scientific rigor. This process ensures that your project is meticulously planned, expertly executed, and delivers actionable data on time.

Project Consultation and Design

We initiate with in-depth communication to clarify your research objectives and sample types. Based on this, we customize the detection strategy, selecting the most suitable platform (e.g., LC-MS/MS for absolute quantification or TR-FRET for high-throughput screening) and jointly define the project timeline and deliverables.

Assay Development and Condition Optimization

Prior to formal experiments, we systematically optimize the reaction system. This includes determining optimal cofactor concentrations, buffer conditions, and reaction time, and establishing standard curves to define the linear range and sensitivity of the assay, thereby creating a robust method tailored for your samples.

Sample Processing & Quality Control

Upon receipt, your samples undergo preprocessing and stringent quality checks. This includes measuring protein concentration, verifying substrate integrity, and performing necessary clarification or enrichment steps for complex biological samples to ensure all components meet the experimental requirements.

Activity Measurement & Data Acquisition

Using automated platforms, we execute the enzymatic reactions and acquire raw data via the selected technological platforms (e.g., mass spectrometers, plate readers), completing core experiments such as kinetic time courses or dose-response analyses.

Data Analysis & Reporting

We process the raw data, perform modeling and statistical analysis, and calculate kinetic parameters. The results are then interpreted within the context of your research. Finally, we deliver a comprehensive report containing all data, methodologies, result visualizations, and professional conclusions.

Sample Requirements and Specifications

Enzyme Samples

1. Recombinant TET proteins: >90% purity, concentration ≥0.1 mg/mL, with activity verification
2. Cell lysates: Total protein concentration 1-5 mg/mL, prepared with protease inhibitors
3. Nuclear extracts: Enriched for endogenous TET activities with preservation of cofactors
4. Storage conditions: Aliquot at -80°C in stabilization buffers maintaining Fe (II) sensitivity

DNA Substrates

1. Methylated oligonucleotides: Designed with specific CpG motifs and methylation patterns.
2. Genomic DNA substrates: From defined cell lines with characterized methylation status.
3. Plasmid DNA: Methylated vectors for global oxidation assessment.

Cofactor and Inhibitor Samples

1. α-ketoglutarate: High-purity preparations for kinetic studies.
2. Small molecule compounds: Provided with solubility and stability data.
3. Metal ion solutions: Fe (II) and other cofactors in appropriate buffers.

Service Applications

Biological Sample Analysis

1. Tissue-specific TET profiling in disease models and clinical samples.
2. Stem cell differentiation monitoring through oxidation product dynamics.
3. Cell line characterization for epigenetic drug screening applications.
4. Primary cell analysis from patient-derived samples.

Drug Discovery Support

1. High-throughput screening of TET-targeted compound libraries.
2. Mechanism of action studies for small molecule modulators.
3. Selectivity profiling across TET isoforms and related dioxygenases.
4. ADME-Tox integration for lead optimization programs.

Enzyme Kinetic Characterization

1. Michaelis-Menten kinetics for α-ketoglutarate and DNA substrate utilization.
2. Inhibition constant determination (IC50, Ki values) for TET inhibitors.
3. Processivity analysis for multi-step oxidation reactions.
4. Cofactor dependency studies including Fe (II) and ascorbate requirements.

Deliverables

Upon project completion, you will receive a comprehensive package containing all critical data and expert analysis to advance your research.

1. A detailed analysis report containing all experimental parameters, raw data, and visual results.
2. Calculated key quantitative parameters such as enzyme kinetic constants and inhibitor IC50 values.
3. All relevant quality control documentation, including standard curves and control experiment results.
4. Professional conclusions drawn from the data and actionable suggestions for follow-up research.

Why Choose Us?

1. Multi-platform Detection Strategy: Combines the strengths of mass spectrometry, fluorescence, and radiometric methods, enabling the accurate quantification of the entire oxidation pathway from 5mC to 5caC within a single study. This approach allows for cross-validation of key findings, ensuring credibility—a critical advantage for complex mechanism studies and inhibitor validation.
2. Specialized Substrate Design: We can synthesize DNA substrates with specific CpG density, flanking sequences, and methylation states to match your genomic region of interest. We also optimize chromatin sample extraction protocols to preserve labile oxidation marks, thereby measuring enzyme activity that more closely reflects the physiological state.
3. Rigorous Quality Assurance: Every experiment includes a complete set of negative, positive, and inhibitor controls, alongside technical replicates and statistical validation. We provide clear quality metrics such as Z'-factors and confidence intervals, ensuring the data meets the high standards required for top-tier publications and drug discovery decision-making.

Frequently Asked Questions (FAQs)

Our TET dioxygenase activity assay service provides the precise, high-quality data you need to dissect the mechanisms of active DNA demethylation. Whether your focus is on developmental biology, cancer epigenetics, or drug discovery, our expert team and multi-platform approach ensure your project's success. Contact us today for a free consultation and a tailored project proposal. We also suggest you to explore other related services on our website, such as DNA methyltransferase (DNMT) activity assay and histone modifying enzyme analysis, to build a comprehensive epigenetic research strategy with CD BioSciences.

Reference

1. An J, Rao A, Ko M. TET family dioxygenases and DNA demethylation in stem cells and cancers[J]. Experimental & molecular medicine, 2017, 49(4): e323-e323.