De Novo Antibody Sequencing with Isoleucine/Leucine Discrimination

A three-in-one solution for obtaining 100% accurate amino acid sequences for antibody proteins 

Obtaining the sequence of monoclonal antibodies (mAbs) is crucial for the development of some novel biotherapeutics. However, the need to extensively characterize mAbs at the molecular level presents a unique challenge to drug developers and manufacturers. To address this difficulty, Bioinformatics Solutions, Inc. (BSI) has developed the proprietary de novo antibody protein sequencing technology, based on their PEAKS AB Software, to sequence antibodies

This de novo antibody sequencing service is a 3-in-1 solution for obtaining 100% accurate amino acid sequences for antibody proteins with unknown sequences. BSI combines state-of-the-art top-down and bottom-up mass spectrometry (MS) technologies to achieve high accuracy of the constructed sequence with amino acid-level confidence.

Discriminating isoleucine from leucine

The latest EThcD (electron-transfer/higher-energy collision dissociation) fragmentation scheme is incorporated into the bottom-up MS workflow. The rich MS/MS spectra derived from EThcD fragmentation not only improves the accuracy and sensitivity of de novo sequencing but also generates signature w-ion for direct discrimination of the isobaric amino acids, isoleucine, and leucine. In turn, from their bottom-up MS analysis, BSI derives the antibody protein sequences with isoleucine and leucine differentiation by the EThcD method.

Addressing antibody heterogeneity challenges

In addition, the top-down MS workflow focuses on the intact mass of light and heavy chains. This addresses the antibody heterogeneity issues such as C-terminal lysine truncation and glycan forms, which cannot be well answered by bottom-up methods. The top-down MS result can also further validate the bottom-up sequencing result.

By integrating bottom-up MS analysis with EThcD and top-down MS approaches, the de novo antibody sequencing with Ile/Leu differentiation service offered by BSI can guarantee 100% sequence accuracy.

Overall, the industry demands more extensive and accurate characterization of antibodies, and BSI strives to answer this call. With continuous improvement and optimization, BSI sets to provide the most robust next-generation protein sequencing. Learn more.