Chemical Proteomics: Principles, Methods and Applications

In modern proteomics research, data-dependent or targeted acquisition strategies such as DDA, DIA, and PRM are widely used to reveal protein expression profiles and abundance changes. However, these methods focus more on the 'presence' and 'quantity' of proteins, making it difficult to directly reflect the functional state of proteins, such as enzyme activity, drug binding sites, or conformational changes. To fill this gap, Chemical Proteomics has emerged. By introducing 'reactive probes' or 'clickable modification groups' and combining with mass spectrometry, it achieves selective labeling and precise analysis of active proteins, functional sites, or potential drug targets, becoming a tool for new drug development and functional protein research.

 

1. Basic Principles of Chemical Proteomics

1. What is Chemical Proteomics?

Chemical Proteomics is a research strategy that combines small molecule chemical probes with proteomics, utilizing covalent reactions, specific affinity, or bioorthogonal chemistry to label, enrich, and mass spectrometry detect target proteins, thereby identifying the active state, modification sites, or drug binding targets of proteins.

 

2. Three Key Elements

(1) Functional Chemical Probes: Specifically recognize certain types of proteins or active sites (such as serine esterases, cysteine proteases)

(2) Selective Modification Reactions: Such as nucleophilic addition, click chemistry

(3) High-Resolution Mass Spectrometry Analysis: Qualitative and quantitative analysis of modified proteins or peptides

 

2. Mainstream Strategies and Method Classifications

1. Activity-Based Protein Profiling (ABPP)

• Utilizes covalent probes to selectively label enzyme active sites, commonly used for functional enzyme detection and inhibitor screening;

• Probe structures typically include recognition groups, reactive groups, and enrichable tags;

• Applied in activity profiling of esterases, proteases, and development of novel inhibitors.

 

2. Target Spectrum Analysis of Targeted Covalent Inhibitors

• Design small molecule inhibitors as structural units with chemical probe functions;

• Combine competitive binding experiments and click chemistry to achieve covalent capture with target proteins;

• Used to validate drug mechanisms, assess off-target effects.

 

3. Universal Labeling Method Based on Reactive Residues

• Utilizes universal reactive groups (such as IA-alkyne labeling of Cys residues) to label active sites on protein surfaces;

• Suitable for studying conformational changes, changes in residue accessibility after ligand binding, etc.;

• Can be used for protein stability studies such as heat transfer spectrometry.

 

4. Chemical labeling combined with quantitative mass spectrometry (chemical quantitative proteomics)

• Combine with quantitative methods such as SILAC, TMT, iTRAQ to achieve relative or absolute comparison of modification levels under different treatment conditions;

• Supports time series analysis and multi-group experimental condition comparison;

• Commonly used in studies of dynamic processes such as drug treatment, stress response, and metabolic interference.

 

III. Advantages and Characteristics of Chemical Proteomics

  

Characteristics	Description
Strong target specificity	Can selectively label active enzymes or specific residues, precisely identifying functional proteins
High operability	Probe structures can be customized to fit different research subjects
Supports structure-function correlation analysis	Can evaluate conformational changes in small molecule-protein binding, aiding in structure optimization
Wide application in drug development	Supports first-in-class drug target discovery and validation, evaluation of off-target effects, study of resistance mechanisms, etc.

 

IV. Typical Application Scenarios

1. First-in-class Drug Target Discovery

For novel small molecule drugs without 'classic target characteristics,' direct action targets can be identified through covalent probes and chemical proteomics, revealing new functional sites on undruggable proteins.

 

2. Target validation and off-target evaluation of covalent inhibitors

Directly observe which proteins small molecules covalently bind to, thereby assessing potential toxicity risks and screening for more selective structures.

 

3. Functional proteomics and active enzyme mapping

For example, perform a panoramic scan of the activity of key enzymes such as esterases and proteases in different tissues and disease states.

 

4. Analysis of small molecule-induced conformational changes and residue accessibility

Infer how small molecules affect protein conformation through changes in the protein modification profile, predict 'regulatory sites,' and achieve precise regulation.

 

Biotai Pek Biotech possesses the capability forProbe design → Reaction system optimization → Protein enrichment → Mass spectrometry analysis → Data interpretationfull-process service capability:

• Multi-type chemical probe platform: Support for commercial probes and custom synthesis (including bioorthogonal modifications)

• High-sensitivity mass spectrometry system: Equipped with Orbitrap Exploris 480 and TripleTOF platforms to ensure detection sensitivity

• Target mining + pathway analysis: Complemented by high-throughput bioinformatics analysis to identify significantly enriched targets and their biological functions

 

Chemical proteomics in the post-genomic era provides a refined and operable research path for functional protein studies and drug mechanism exploration. By constructing selective labeling systems and mass spectrometry detection platforms, this strategy can deeply reveal the active state and dynamic interactions of proteins and is widely applied in cutting-edge research and drug development in areas like oncology, immunity, and metabolism. In the future, with the expansion of probe diversity, upgrades in quantitative methods, and enhanced AI-assisted analytical capabilities, chemical proteomics will play an increasingly important role in precision medicine and innovative drug research and development.

 

Biotai Pek Biotech - Characterization of biological products, high-quality multi-omics biomolecular mass spectrometry detection service provider

 

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