De Novo Monoclonal Antibody Sequencing: Technical Analysis, Advantages and Applications

1. What is De Novo Monoclonal Antibody Sequencing?

De Novo Antibody SequencingThis refers to a technique that does not rely on reference databases, using high-resolution mass spectrometry (LC-MS/MS) to analyze the MS/MS fragment of enzymatically digested antibody peptides. Algorithms are used to deduce the amino acid sequence step-by-step from the fragment peak maps, piecing together the complete monoclonal antibody sequence.

 

Unlike traditional database-dependent sequencing, De Novo sequencing does not require any known genetic information or reference sequences, itstarts completely from the protein to restore the structure.Especially for antibodies, the most critical regions are the **Variable regions** containing Complementarity Determining Regions (CDRs), which are difficult to find in public databases. Therefore, only De Novo sequencing can truly achieve structural analysis of highly variable antibodies.

 

In a complete process, a high-quality monoclonal antibody De Novo sequencing project typically includes the following steps:

• Antibody protein sample purification and quality control;

• Multi-enzyme digestion (Trypsin, Chymotrypsin, etc.) to generate high-coverage peptide fragments;

• High-resolution mass spectrometry to collect fragment spectra of peptides;

• Using De Novo algorithms (such as PEAKS, Novor) for peptide sequence inference;

• Sequence assembly and complete structure reconstruction;

• Manual proofreading, modification identification, modeling comparison, and (optional) expression verification.

 

2. Technical Advantages: Why Choose De Novo Monoclonal Antibody Sequencing?

1. Does not rely on genes, not limited by expression
Many antibody samples (such as those from clinical sources, animal immunization, third-party procurement) cannot obtain original B cells or expression vectors, making traditional gene sequencing methods infeasible. De Novo sequencing starts directly from the protein, requiring no DNA/RNA information, and isthe only applicable method for structural analysis.。

 

2、Highly adaptable to structural variation, covering critical regions like CDR
The variable regions of antibodies, especially the CDR1~3 areas, are the core of functional sites, but these sequences are highly variable and almost impossible to find matching in databases. De Novo sequencing is based on actual mass differences between fragments,naturally supporting the identification of new variants and structures,making it suitable for antibody engineering design and affinity modification research.

 

3、Simultaneously identifies modification information, revealing true antibody conformation
Antibodies naturally have post-translational modifications (PTMs) such as glycosylation, deamidation, oxidation, which often determine stability and function. De Novo sequencing can parse sequences whilesimultaneously capturing modification sites and types,revealing the true state of antibodies in expression systems.

 

4、Can be extended as an expression template for structural reproduction
Through reverse sequence design, De Novo results can be directly converted into cDNA templates, enabling recombinant antibody expression. Suitable for old antibody reproduction, functional verification, structural modeling, and patent circumvention designs.

 

3. Practical Application Scenarios: From Research Exploration to Industrial Transformation

1. Old Antibody Sequence Retrospective

When a laboratory has a functional antibody (unknown/lost source) that needs to be used for recombinant expression or patent registration, De Novo sequencing can restore the complete structure to achieve functional "replication."

 

2. Commercial Antibody Comparison and Verification

Used to analyze whether antibodies of the same label produced by different manufacturers are truly identical and if there are mutations, modification differences, or batch variations.

 

3. Consistency Studies in Antibody Drug Development

Conduct structural comparison and consistency evaluation of antibody drugs produced in different expression systems (e.g., CHO vs. HEK293) and under different process conditions to meet IND/BLA application material requirements.

 

4. Antibody Patent Design and Circumvention

Based on De Novo results, identify structural features of authorized antibody drugs and design "bypass antibodies" with sequence differences but similar functions to assist IP strategy planning in new drug research and development.

 

5. Antibody Screening in Vaccine or Immunization Research

From animal immune serum, use De Novo monoclonal antibody sequencing to dig out key CDR sequences of high-affinity antibodies for recombinant screening and affinity maturation.

 

4. De Novo Antibody Sequencing Solutions by BGI Tech

At BGI Tech, we have constructed a De Novo platform focused on antibody-level structural analysis, integrating experimental strategies, data processing, and bioinformatics for comprehensive delivery, ensuring each project is equipped withhigh coverage, high accuracy, and high recombinability.。

1、Multi-enzyme parallel digestion design: Enhancing the ability to identify "difficult-to-cover regions" like CDR;

2、Dual-platform mass spectrometry (Orbitrap × timsTOF): Balancing resolution and throughput;

3、Proprietary assembly algorithm + manual review mechanism: Ensuring sequence accuracy;

4、Modification recognition, structure modeling, differential comparison and other value-added modules: Supporting research to IND application;

5、Optional CHO expression verification service: Closed-loop delivery from protein to function.

We have successfully completed hundreds of antibody structure analysis and expression projects for antibody pharmaceutical companies, research hospitals, vaccine companies, and university research groups, widely applied intasks such as old antibody reproduction, drug consistency comparison, structural difference analysis, and immune profile screening.

 

In scenarios where the antibody function is clear but the sequence is unknown, De Novo monoclonal antibody sequencing provides a feasible, scientific, and efficient path for structural reconstruction. It not only solves the issue of 'sequence availability' but also helps researchers move towards the goal of 'controllable structure, reproducible expression, and patent planning.' If you have antibody samples with untraceable sequence origins, or if you are in the stage of antibody expression, reconstruction, or consistency research,De Novo antibody sequencing is worth considering as a core technical option. Feel free to contact the Bioytek Technology team to obtain sample evaluations, project plans, and reference reports.

 

Bioytek Biotechnology — a high-quality service provider for bioproduct characterization and multi-omics mass spectrometry analysis

 

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De Novo Sequencing