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.