MtoZ Biolabs provides dedicated Protein Citrullination Analysis Service to support researchers studying citrullinated proteins in targeted or discovery-driven projects. Through optimized enrichment approaches and high-resolution LC-MS/MS, we deliver reliable qualitative identification of citrullinated residues that contribute to inflammatory signaling, autoimmunity, chromatin regulation, and disease-related cellular responses. Our service helps clients verify modification sites, define modification patterns and generate high-quality data for mechanistic or exploratory investigations.
Overview
Protein citrullination is a post-translational modification catalyzed by the peptidylarginine deiminase (PAD) family. During this calcium-dependent reaction, arginine residues are converted into citrulline, resulting in the loss of a positive charge and potential changes to protein structure or binding properties. Citrullination is irreversible and has been linked to immune activation, epigenetic regulation, apoptosis, and diverse pathological conditions such as rheumatoid arthritis, multiple sclerosis, cancer, and neurodegenerative disease.
Characterizing citrullinated proteins provides valuable insights into disease mechanisms, supports biomarker discovery and facilitates functional research into PAD-mediated regulatory pathways.
Figure 1. The Chemical Conversion of Arginine to Citrulline
Technical Principles
Our Protein Citrullination Analysis Service integrates specialized enrichment methods with high-resolution LC-MS/MS. Citrullinated peptides often occur at low abundance and lack strong intrinsic enrichment properties, so we employ optimized strategies such as:
- Citrulline-reactive bead (CRB) enrichment
- Chemical derivatization using biotin-based tagging (BPG)
- Anti-citrulline immunoaffinity enrichment
These workflows selectively enrich citrullinated peptides while minimizing background from non-modified or deamidated species. Orbitrap-based MS using HCD or EThcD fragmentation provides the high mass accuracy and sequence coverage required for confident site-level identification and distinction from chemically similar modifications.
Protein Citrullination Analysis Service at MtoZ Biolabs
1. Targeted Protein Citrullination Analysis
We offer targeted characterization of citrullination on client-defined proteins. This service provides precise site identification and supports studies focused on validating PAD-regulated modifications, investigating disease-associated protein changes or confirming citrullination events implicated in cellular signaling.
2. Citrullination Proteomics
For broader discovery, we perform proteome-wide identification of citrullinated peptides across complex samples. This high-throughput workflow enables systematic mapping of citrullination patterns, comparison across biological states and exploration of candidate proteins involved in inflammatory or pathological pathways.
Rebak, A. S. et al. Philos Trans R Soc Lond B Biol Sci. 2023.
Figure 2. Citrullination Proteomics Workflow
Why Choose MtoZ Biolabs?
1. Comprehensive Citrullination Profiling
From single-protein validation to global discovery, our workflows deliver high-confidence qualitative identification of citrullinated peptides and modification sites.
2. Advanced Analytical Platforms
High-resolution Orbitrap systems combined with optimized enrichment chemistries ensure sensitive and accurate detection of low-abundance citrullinated peptides.
3. High-Confidence Site Identification
HCD and EThcD fragmentation strategies enable precise distinction between true citrullination and non-enzymatic deamidation.
4. Broad Sample Compatibility
Our workflows support purified proteins, immunoprecipitated complexes, cell lysates, tissue lysates, and extracellular matrix-enriched samples.
5. Customized Project Design
Analytical strategies are tailored based on sample type, biological context, and research objectives to maximize the relevance and clarity of qualitative findings.
Start Your Project with MtoZ Biolabs
MtoZ Biolabs provides high-quality Protein Citrullination Analysis Services focused on the qualitative identification of citrullinated proteins and modification sites. Alongside citrullination, we offer a wide range of qualitative PTM analysis services including phosphorylation, ubiquitination, acetylation, and methylation.
Contact us to discuss a tailored qualitative analysis plan that aligns with your research goals.
FAQ
Q1: What types of samples are suitable?
We accept purified proteins, immunoprecipitated complexes, cell lysates, tissue lysates, and extracellular matrix-enriched samples.
Q2: What is the service general workflow?
Q3: What data formats are provided?
Deliverables include raw MS files, qualitative identification tables, annotated spectra, site-localization information, and a comprehensive PDF report.
Q4: How should I prepare my samples?
Use PAD inhibitors during lysis, avoid harsh detergents, and submit samples as fresh or snap-frozen lysates with adequate protein quantity. For more information, please refer to Sample Submission Guidelines for Proteomics.
If you are unsure about sample preparation, our team is available for consultation and can guide you through the process to ensure optimal results.
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