An Acetyl-Click Chemistry Assay to Measure Histone Acetyltransferase 1 Acetylation
January 26th, 2024
Quick and accurate chemical assays to screen for specific inhibitors are an important tool in the drug development arsenal. Here, we present a scalable acetyl-click chemistry assay to measure the inhibition of HAT1 acetylation activity.
Our developed acetyl-click assay serves as a tool to assess HAT1 acetyl transferase activity, which is key in isolating H4 histones before nucleosome incorporation. We aim to use this method for high throughput screening of small molecule inhibitors against the HAT1 enzyme. This method measures enzymatic activity directly on the peptide substrate.
This offers advantages compared to other enzymatic assays by avoiding biologic variability and antibody related costs. This is also high throughput and can be adapted to use with other acetyl transferases. We have recently published a small molecule HAT1 inhibitor based on this assay that has activity in cells and animals.
We continue to use this assay to screen additional chemical libraries and perform structure activity relationships. We are advancing methods to track histone production, folding, chaperoning, and chromatin integration. This highlights the need for improved chemical tools to explore biological mechanisms and stimulate drug discovery.
Our goal is to demonstrate that targeting histone production can have therapeutic benefit for diseases such as cancer.
Overview
This article presents a scalable acetyl-click chemistry assay designed to measure the inhibition of HAT1 acetylation activity. The assay serves as a valuable tool for high throughput screening of small molecule inhibitors against the HAT1 enzyme.
Key Study Components
Area of Science
- Biochemistry
- Drug Development
- Enzymology
Background
- HAT1 acetyl transferase activity is crucial for isolating H4 histones.
- Current methods may involve biologic variability and high costs.
- High throughput screening is essential for efficient drug discovery.
- Small molecule inhibitors can impact HAT1 activity in cells and animals.
Purpose of Study
- To develop a reliable assay for measuring HAT1 activity.
- To facilitate the screening of potential small molecule inhibitors.
- To provide a method that minimizes variability and costs associated with traditional assays.
Methods Used
- Acetyl-click chemistry assay for HAT1 activity measurement.
- Direct measurement of enzymatic activity on peptide substrates.
- Adaptation of the method for other acetyl transferases.
- High throughput capabilities for screening applications.
Main Results
- The assay effectively measures HAT1 acetylation activity.
- Demonstrated advantages over traditional enzymatic assays.
- Successful identification of a small molecule HAT1 inhibitor.
- Inhibitor shows activity in cellular and animal models.
Conclusions
- The acetyl-click assay is a valuable tool for drug development.
- It provides a scalable and efficient method for screening inhibitors.
- This approach can be adapted for various acetyl transferases.
Frequently Asked Questions
Executive Industry Relevance
Direct measurement of HAT1 acetyltransferase activity using an acetyl-click chemistry assay enables high-throughput identification of small molecule inhibitors, addressing a critical need in early oncology drug discovery. This platform reduces biological variability and operational costs, supporting robust target validation and mechanistic de-risking for chromatin-modifying enzyme programs. Its scalability and adaptability position it as a reusable asset for portfolio-wide screening and lead identification.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables direct interrogation of HAT1 enzymatic function for target validation.
- Supports mechanistic de-risking by quantifying inhibitor effects on substrate acetylation.
- Facilitates rapid triage of chemical matter based on functional readouts.
Screening & Assay Development
- Provides a standardized, antibody-free assay for reproducible high-throughput screening.
- Generates quantitative fluorescence outputs for reliable compound ranking.
- Reduces biologic variability, improving assay robustness and scalability.
Translational & Preclinical Research
- Enables structure-activity relationship studies to optimize inhibitor potency and selectivity.
- Supports continuity from biochemical screening to cellular and in vivo validation.
- Facilitates exploration of histone production and chromatin integration mechanisms relevant to disease models.
Pipeline & Workflow Integration
This assay integrates at the interface of early discovery and lead identification, providing a bridge from biochemical target validation to preclinical candidate selection.
- Discovery Biology: Quantifies HAT1 activity and inhibitor impact, supporting hypothesis-driven target assessment.
- Screening: Delivers reproducible, scalable outputs for compound library evaluation.
- Analytics: Provides quantitative fluorescence measurements for comparative analysis of inhibitor efficacy.
- Translational Research: Aligns biochemical findings with downstream cellular and animal studies for translational continuity.
- Enterprise Reuse: Adaptable to other acetyltransferases, enabling platform extension across epigenetic targets.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in target engagement and inhibitor mechanism.
- Operational Value: Streamlines assay setup, reduces costs, and enhances throughput.
- Strategic Value: Improves go/no-go decision quality and accelerates early-stage portfolio progression.
- Portfolio Impact: Supports risk-adjusted prioritization of epigenetic targets and chemical series.
Implementation Considerations
- Requires expertise in enzymology, click chemistry, and fluorescence detection.
- Needs access to recombinant protein production and analytical plate readers.
- Demands cross-team standardization for data comparability in screening campaigns.
- Adaptable to other acetyltransferases with appropriate substrate and enzyme selection.
- Assay performance may depend on peptide substrate quality and reagent consistency.
