Protein Sequencing Service by Mass Spectrometry

    Mass spectrometry-based sequence analysis of proteins, antibodies, peptides, and other samples involves the analysis of the sample's amino acid sequence. Mass spectrometry sequencing refers to the determination of the primary structure of amino acid sequences based on mass spectrometry. Before moving on to mass spectrometry sequence analysis, we provide a brief introduction to a few definitions. Amino acids are organic compounds containing amino (-NH2) and carboxyl (-COOH) functional groups and a side chain (R group) specific to each amino acid. Peptides are short chains composed of two to fifty amino acids linked by peptide bonds. Polypeptides are longer, continuous, unbranched peptide chains, containing up to about fifty amino acids. Peptides/polypeptide chains containing more than fifty amino acids are referred to as proteins. Proteins consist of one or more polypeptides arranged in a biologically functional group manner, typically able to bind to ligands (such as coenzymes and cofactors), another protein, other large molecules (such as DNA or RNA), or more complex macromolecular assemblies. Antibodies (Ab), also known as immunoglobulins (Ig), are large Y-shaped proteins primarily produced by plasma cells, used by the immune system to neutralize pathogens, such as pathogenic bacteria and viruses.


    Compared to the Edman degradation method, the advantages of mass spectrometry sequencing are that it is more sensitive, can cleave peptides faster, and can identify terminally blocked or modified protein samples. MtoZ Biolabs utilizes existing high-resolution mass spectrometry technology platforms to provide mass spectrometry-based sequence analysis services, achieving 100% coverage of the targeted protein sequence.



    Figure 1. Mass Spectrometry Sequencing Diagram


    The process of protein sample sequence analysis generally only uses Trypsin for proteolytic digestion of the protein, with peptide coverage of approximately 60%. To obtain the full sequence information of the target protein, MtoZ Biolabs selects six common proteases (Trypsin, Chymotrypsin, Asp-N, Glu-C, Lys-C, and Lys-N) used in the protein sequence analysis process to perform enzymatic digestion and mass spectrometry on the target protein. In the process of obtaining fragmented peptide fragments, the complete protein sequence is determined by splicing the peptide fragments. MtoZ Biolabs uses the Thermo company's newly launched Orbitrap Fusion Lumos mass spectrometer for protein sample sequence analysis. The Orbitrap Fusion Lumos mass spectrometer is currently the highest resolution and sensitivity mass spectrometer, ensuring the sensitivity of identification of low-abundance peptide fragmentation fragments; it also adopts a combination of HCD and ETD modes during the peptide fragmentation process to ensure the integrity of the peptide fragmentation fragments. This can achieve N-terminal, C-terminal sequence analysis, and full-length protein sequence analysis. For samples with an unknown theoretical sequence, de novo sequencing can be performed for sequence analysis.

  • • Antibody Sequencing Service

    High-quality, active, and effective antibody is a multi-billion-dollar industry. Merely having hybridoma cells is not enough due to potential risks such as storage accidents, genetic drift, or contamination. Therefore, performing sequence analysis on an antibody ensures that the antibody can be recombinantly produced at any time. Additionally, if you have obtained an effective antibody and wish to protect its intellectual property or expand its production, obtaining accurate antibody sequence is essen......

  • • Peptide Sequencing Service

    Thousands of naturally identified peptides have been recognized, playing important roles in human physiological processes, including as hormones, neurotransmitters, growth factors, ion channel ligands, or anti-infectives. Peptide drugs are considered to have high selectivity and efficacy, as well as relative safety and good tolerance. Therefore, interest in peptide drugs in drug research and development (R&D) is increasing, with hundreds of peptide drugs undergoing clinical trial evaluation.

  • • Protein Sequencing Service

    The primary structure of a protein refers to the linear sequence of amino acids that make up its polypeptide chain. Protein sequencing, protein sequence analysis, protein primary structure analysis, and protein amino acid sequence analysis are all processes that determine the full amino acid sequence of a protein.

  • • Peptide Sequencing Service by Mass Spectrometry

    Peptides are biological macromolecules composed of two or more amino acids linked by peptide bonds, exhibiting diverse biological functions. Tandem mass spectrometry (MS/MS) peptide sequencing identifies the amino acid composition and sequence of proteins or peptides using MS/MS. In the initial MS stage, peptide fragments are ionized and analyzed based on their mass-to-charge ratio (m/z), resulting in a MS1 that reflects the m/z and relative abundance of the peptide fragments.

  • • Top-Down Protein Sequencing Service

    In top-down proteomics analysis, intact protein molecular ions generated by ESI or MALDI are introduced into a mass analyzer and undergo gas-phase fragmentation. Top-down analysis facilitates the direct observation of C-terminal and N-terminal truncations and the differentiation of isomers through different sequences.

  • • N- and C-Terminal Protein Sequencing Services


  • • Unknown Proteins Sequencing Service

    The amino acid sequence of proteins forms the basis for determining protein structure and function. Protein sequencing, which determines the types and arrangement of amino acids composing a protein, is a crucial aspect of proteomic studies. Common methods include mass spectrometry (such as tandem mass spectrometry) and the Edman degradation method.

  • • Protein Mutation Analysis Service

    Protein mutation refers to the alteration in the amino acid composition or sequence of a protein, which subsequently leads to changes in the structure and function of the protein. Protein mutations can occur naturally or be induced artificially.

  • • De Novo Sequencing Service

    MtoZ Biolabs provides de novo sequencing service for monoclonal antibodies and proteins, with no need for database searching.

  • • Protein Full-Length Sequencing Service

    MtoZ Biolabs uses up to 6 enzymes for protein digestions, coupled with high resolution LC-MS/MS techniques, ensuring 100 percent protein sequence coverage.

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