Proteochemometric modeling of the antigen-antibody interaction: new fingerprints for antigen, antibody and epitope-paratope interaction

PLoS One. 2015 Apr 22;10(4):e0122416. doi: 10.1371/journal.pone.0122416. eCollection 2015.

Abstract

Despite the high specificity between antigen and antibody binding, similar epitopes can be recognized or cross-neutralized by paratopes of antibody with different binding affinities. How to accurately characterize this slight variation which may or may not change the antigen-antibody binding affinity is a key issue in this area. In this report, by combining cylinder model with shell structure model, a new fingerprint was introduced to describe both the structural and physical-chemical features of the antigen and antibody protein. Furthermore, beside the description of individual protein, the specific epitope-paratope interaction fingerprint (EPIF) was developed to reflect the bond and the environment of the antigen-antibody interface. Finally, Proteochemometric Modeling of the antigen-antibody interaction was established and evaluated on 429 antigen-antibody complexes. By using only protein descriptors, our model achieved the best performance (R2 = 0.91, Qtest(2) = 0.68) among peers. Further, together with EPIF as a new cross-term, our model (R2 = 0.92, Qtest(2) = 0.74) can significantly outperform peers with multiplication of ligand and protein descriptors as a cross-term (R2 ≤ 0.81, Qtest(2) ≤ 0.44). Results illustrated that: 1) our newly designed protein fingerprints and EPIF can better describe the antigen-antibody interaction; 2) EPIF is a better and specific cross-term in Proteochemometric Modeling for antigen-antibody interaction. The fingerprints designed in this study will provide assistance to the description of antigen-antibody binding, and in future, it may be valuable help for the high-throughput antibody screening. The algorithm is freely available on request.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / chemistry*
  • Antibodies / immunology
  • Antigen-Antibody Complex / chemistry*
  • Antigens / chemistry*
  • Antigens / immunology
  • Epitopes / chemistry
  • Epitopes / metabolism
  • Humans
  • Models, Molecular
  • Peptide Mapping*

Substances

  • Antibodies
  • Antigen-Antibody Complex
  • Antigens
  • Epitopes

Grants and funding

This work was supported in part by grants from National Natural Science Foundation of China (31200986, 31171272) and Ministry of Science and Technology China (2010CB833601). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.