De Novo Protein Sequencing Service

Protein sequences are critical information for study of protein function, as the amino acid sequence determines the advanced protein structures. Generally, there are two methods for protein sequence analysis, database search and de novo sequencing. Database search method identifies proteins by measuring peptide mass, and comparing to available protein databases. However, this method is unsuitable for analyzing antibodies, peptides, and proteins, of which the sequence information is either inaccessible, or not included in any databases. For these cases, de novo sequencing is the only way to decipher the protein sequence. MtoZ Biolabs uses the most advanced mass spectrometer-Orbitrap Fusion Lumos, for de novo sequencing service. Coupled with our professional bioinformatics analysis and reverse sequence confirmation, high-quality sequence analysis is guaranteed. Our de novo sequencing service is also well-suited for analyzing multiple kinds of antibodies, including IgM and IgG antibody subtypes, and antibodies modified with FITC, biotin, and Alexa, etc.

Analysis Workflow

Applications

1. Sequence Analysis of Protein/Peptide, of which Databases are Unavailable

2. PTMs Analysis of Protein/Peptide, of which Databases are Unavailable

3. Sequence Analysis of CDR Region or Full-Length of Antibodies

Case Study

In this study, the full-length sequence of a monoclonal antibody is analyzed by our de novo sequencing system. MS/MS data in Fig. 1 indicated that complete fragmentation of peptide precursors and L/I residues can be easily discriminated after second collision. We used four enzymes (indicated by different color in Fig. 2) for protein digestion. Peptide mapping results showed complete sequence coverage with CDR being identified by at least 10 times, reaffirming accuracy of our sequence analysis.