Homo-Tag-Assembler Assay for Full-Length Antibody Sequencing

Antibodies are proteins produced by the immune system in response to antigens. Determining the sequence of purified unknown antibodies remains difficult due to factors like incomplete sequence coverage, ambiguous isobaric residues (I/L), and unstable assembly processes. To overcome these issues, we developed the Homo-Tag-Assembler, a software tool using a homology tag fuzzy string matching algorithm. By analyzing amino acid distributions from many similar antibody variable region sequences, we created a probability table specific to these regions. This helped evaluate peptide similarity during de novo sequencing, distinguish peptides from light and heavy chains, and differentiate leucine from isoleucine. Testing with the Herceptin antibody showed full-length sequence coverage with accuracy of 99.1% for the light chain and 100% for the heavy chain variable regions. This method uses conserved regional features and homology based information to enable accurate full-length antibody sequence reconstruction.