Cysteinylation Analysis Service

Cysteinylation is a reversible post-translational modification that involves the covalent addition of a cysteine residue to free thiol groups within proteins, typically through disulfide bond formation. This modification plays an important role in regulating protein redox status, structure, and function. MtoZ Biolabs offers a comprehensive Cysteinylation Analysis Service designed to identify, quantify, and interpret cysteinylation events with high accuracy. We integrates complementary analytical strategies to ensure sensitive, specific, and biologically meaningful results. MtoZ Biolabs supports both targeted and global cysteinylation analysis. 

1. Target Protein Cysteinylation Analysis

This analysis is designed for researchers interested in evaluating cysteinylation on a specific protein. MtoZ Biolabs can identify modified cysteine sites, assess modification levels, and compare changes across experimental conditions. This focused workflow is ideal for validating modification events, determining functional relevance, and studying redox-dependent regulation of individual proteins involved in signaling or enzymatic activity.

2. Cysteinylation Proteomics

For broader discovery-driven projects, MtoZ Biolabs offers cysteinylation proteomics, enabling proteome-wide identification and quantification of cysteinylated proteins. We systematically map cysteinylation sites and evaluate global modification patterns. This large-scale approach supports pathway analysis, redox network mapping, and comparative profiling across tissues, disease models, or oxidative stress conditions.

Because cysteinylation is a dynamic and low-abundance post-translational modification, multiple approaches are required to achieve accurate detection and quantification. Our service portfolio includes:

🔸Mass Spectrometry-Based Analysis

High-resolution LC-MS/MS represents the gold standard for mapping cysteinylation sites with precision. By combining selective enrichment strategies with Orbitrap-based mass spectrometry, we provide site-specific identification, relative or absolute quantification, and proteome-wide profiling of cysteinylated proteins. This approach enables both hypothesis-driven targeted analysis and discovery-oriented studies across complex biological samples.

🔸Antibody-Based Detection

Immunological approaches, including cysteinylation-specific antibodies or antibodies recognizing cysteine modifications after derivatization, provide robust tools for validating modification status in specific proteins. These assays are particularly suited for targeted investigations, allowing semi-quantitative assessment and confirmation of results obtained through proteomic analysis.

🔸Fluorescence-Based Methods

Fluorescent thiol-reactive probes and cysteine-specific labeling reagents offer highly sensitive detection of cysteinylated proteins. These techniques allow monitoring of modification dynamics in real time, facilitate single-protein or cellular assays, and provide complementary information on the localization and relative abundance of cysteinylation events.

What is Cysteinylation?

Cysteinylation is a thiol-based post-translational modification in which a free cysteine forms a disulfide bond with protein cysteine residues. As a reversible redox modification, it plays dual roles in protecting cysteine residues from irreversible oxidation and in modulating protein function. This modification can alter enzymatic activity, protein stability, and intermolecular interactions, thereby influencing cellular signaling and stress responses.

Ayalew, L. et al. MAbs. 2020.

Figure 1. Depictions of Doubly Cysteinylated and Classically Linked IgG2-A Forms

Advances in proteomics have demonstrated that cysteinylation occurs widely across metabolic enzymes, structural proteins, and regulatory factors. Dysregulation of cysteinylation has been implicated in cardiovascular dysfunction, neurodegeneration, diabetes, and cancer, highlighting its potential as both a biomarker of oxidative stress and a target for therapeutic intervention. Accurate identification and quantification of cysteinylation are therefore essential for understanding its biological significance and clinical relevance.

Analysis Workflow

Sample Submission Suggestions

1. Sample Types

Cells, tissues, serum, plasma, or purified proteins. For other sample types, please contact us for customized guidance.

2. Storage

Snap-freeze samples in liquid nitrogen and store at –80°C.

3. Shipping

Ship samples on dry ice to maintain stability.

4. Replicates

Biological replicates are recommended for reliable statistical analysis.

Service Advantages

✅ High Sensitivity and Specificity: Advanced enrichment and high-resolution LC-MS/MS enable detection of low-abundance modifications.

✅ Customized Workflows: Flexible experimental designs adapted to specific research goals and sample types.

✅ Expertise in Redox Proteomics: A dedicated team with strong backgrounds in PTM analysis.

✅ Efficient Project Delivery: Streamlined workflows and project management ensure fast turnaround without sacrificing quality.

Applications

Cysteinylation analysis supports a wide range of research applications, including:

1. Redox Regulation

Mapping cysteine modifications that regulate protein function under oxidative stress.

2. Signal Transduction

Identifying cysteinylation events that modulate receptor, kinase, and transcription factor activity.

3. Disease Mechanisms

Understanding abnormal cysteinylation in cardiovascular disorders, diabetes, neurodegeneration, and cancer.

4. Biomarker Discovery

Detecting cysteinylated proteins as indicators of oxidative stress, inflammation, or aging.

5. Drug Development

Assessing how therapeutic compounds alter redox balance and cysteinylation status.

Deliverables

1. Comprehensive Experimental Details

2. Materials, Instruments, and Methods

3. Total Ion Chromatogram & Quality Control Assessment

4. Data Analysis, Preprocessing, and Estimation

5. Bioinformatics Analysis

6. Raw Data Files

By choosing MtoZ Biolabs as your partner, you gain access to an advanced analytical platform that delivers actionable insights into cysteinylation biology, supporting discovery research, biomarker identification, and therapeutic development. Free project evaluation, welcome to learn more details!