What is protein sequencing

1. Background Introduction

Protein sequencing can directly reveal the amino acid sequence of proteins, which is fundamental to understanding protein structure and function. After sequencing, the three-dimensional structure of a protein can be predicted, further elucidating its biological functions and interaction mechanisms. This is of great significance for uncovering the mysteries of life activities and understanding the occurrence and development of diseases. Current protein sequencing technologies mainly include: de novo mass spectrometry sequencing, Edman degradation, and nanopore sequencing. Among them, mass spectrometry-based de novo protein sequencing is widely used. De novo protein sequencing is a novel sequencing technology that directly determines the amino acid sequence of a protein without relying on any known sequence or protein database information. This technology is particularly effective for identifying novel proteins. As antibodies are indispensable molecules in our immune system and valuable tools in medical diagnosis and treatment, de novo protein sequencing has important applications in the field of antibodies.

 

2. Technical Process

Mass spectrometry-based protein sequencing utilizes mass spectrometers to gather mass information of peptide amino acid sequences, known as secondary spectra. Through de novo sequencing algorithms, peptide sequences are deciphered directly from the secondary mass spectra, and after sequence assembly, the complete amino acid sequence of the protein is obtained. The technical process of mass spectrometry-based protein sequencing is as follows: sample preparation → protein enzymatic digestion → peptide separation → mass spectrometry detection → data analysis. Key considerations for mass spectrometry protein sequencing include: ① During sample preparation, avoid protein degradation as much as possible; ② Select appropriate enzymes for protein digestion; ③ Ensure stable performance of the mass spectrometer to improve data accuracy.

 

3. Research Case

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell disorder characterized by the presence of a predominant monoclonal antibody (M protein) in the serum. The authors used liquid chromatography-mass spectrometry (LC-MS) to analyze IgG1-type M protein in human serum. Multiple proteases were used to cleave the M protein, and de novo sequencing methods were employed to decipher antibody peptide fragments. After peptide assembly, the complete heavy and light chain sequences of the M protein were determined. Additionally, the authors characterized the glycosylation levels within the antibody CDR regions.

 

Protein sequencing aids in discovering new drug targets, providing critical information for drug design and screening. Through sequencing technologies, scientists can identify disease-related proteins and design drugs targeting these proteins for precise treatment. With protein sequencing technology, physicians can more accurately assess a patient's disease status and predict disease progression trends, allowing for more personalized treatment plans. This not only enhances therapeutic effectiveness but also reduces side effects, improving patient quality of life.

 

Beijing Biotech-Pack Technology Co., Ltd. has developed antibody sequence analysis software based on literature published in Nature Biotechnology and the Journal of Proteome Research (JPR), combined with existing professional background knowledge. Utilizing proprietary mass spectrometry data computation methods, the software follows the principle of broad input and narrow output, ensuring accurate identification of antibody/protein sequences without missing any valuable data. The sequencing process uses Orbitrap Eclipse and Orbitrap Fusion Lumos mass spectrometers with the highest resolution and sensitivity, ensuring data quality and result accuracy. The protein/antibody sequencing project duration is 3 to 4 weeks.

 

4. Literature References

[1]albertj,denboer,arjand,et al.Direct Mass Spectrometry-Based Detection and Antibody Sequencing of Monoclonal Gammopathy of Undetermined Significance from Patient Serum: A Case Study[J].Journal of Proteome Research, 2023, 22(9):3022-3028.

[2]Bandeira N, Pham V, Pevzner P, et al. Automated de novo protein sequencing of monoclonal antibodies [J]. Nature Biotechnology, 2008, 26(12):1336-1338

 

Biotech-Pack Technology--Bioproduct Characterization, High-quality Multi-omics Mass Spectrometry Detection Service Provider

 

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Protein Sequencing