Structure-based prediction of asparagine and aspartate degradation sites in antibody variable regions

PLoS One. 2014 Jun 24;9(6):e100736. doi: 10.1371/journal.pone.0100736. eCollection 2014.

Abstract

Monoclonal antibodies (mAbs) and proteins containing antibody domains are the most prevalent class of biotherapeutics in diverse indication areas. Today, established techniques such as immunization or phage display allow for an efficient generation of new mAbs. Besides functional properties, the stability of future therapeutic mAbs is a key selection criterion which is essential for the development of a drug candidate into a marketed product. Therapeutic proteins may degrade via asparagine (Asn) deamidation and aspartate (Asp) isomerization, but the factors responsible for such degradation remain poorly understood. We studied the structural properties of a large, uniform dataset of Asn and Asp residues in the variable domains of antibodies. Their structural parameters were correlated with the degradation propensities measured by mass spectrometry. We show that degradation hotspots can be characterized by their conformational flexibility, the size of the C-terminally flanking amino acid residue, and secondary structural parameters. From these results we derive an accurate in silico prediction method for the degradation propensity of both Asn and Asp residues in the complementarity-determining regions (CDRs) of mAbs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artificial Intelligence
  • Asparagine / chemistry*
  • Asparagine / metabolism
  • Aspartic Acid / chemistry*
  • Aspartic Acid / metabolism
  • Immunoglobulin Variable Region / chemistry*
  • Immunoglobulin Variable Region / metabolism
  • Metabolic Networks and Pathways
  • Models, Molecular
  • Molecular Conformation
  • Proteolysis
  • ROC Curve
  • Structure-Activity Relationship*

Substances

  • Immunoglobulin Variable Region
  • Aspartic Acid
  • Asparagine

Grants and funding

J.F.S. was funded by the Roche PostDoc Fellowship programme. All other authors, except P.C., are current employees of Roche. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.