Computational characterization of B-cell epitopes

Nimrod D. Rubinstein, Itay Mayrose, Dan Halperin, Daniel Yekutieli, Jonathan M. Gershoni, Tal Pupko*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Characterizing B-cell epitopes is a fundamental step for understanding the immunological basis of bio-recognition. To date, epitope analyses have either been based on limited structural data, or sequence data alone. In this study, our null hypothesis was that the surface of the antigen is homogeneously antigenic. To test this hypothesis, a large dataset of antibody-antigen complex structures, together with crystal structures of the native antigens, has been compiled. Computational methods were developed and applied to detect and extract physico-chemical, structural, and geometrical properties that may distinguish an epitope from the remaining antigen surface. Rigorous statistical inference was able to clearly reject the null hypothesis showing that epitopes are distinguished from the remaining antigen surface in properties such as amino acid preference, secondary structure composition, geometrical shape, and evolutionary conservation. Specifically, epitopes were found to be significantly enriched with tyrosine and tryptophan, and to show a general preference for charged and polar amino acids. Additionally, epitopes were found to show clear preference for residing on planar parts of the antigen that protrude from the surface, yet with a rugged surface shape at the atom level. The effects of complex formation on the structural properties of the antigen were also computationally characterized and it is shown that epitopes undergo compression upon antibody binding. This correlates with the finding that epitopes are enriched with unorganized secondary structure elements that render them flexible. Thus, this study extends the understanding of the underlying processes required for antibody binding, and reveals new aspects of the antibody-antigen interaction.

Original languageEnglish
Pages (from-to)3477-3489
Number of pages13
JournalMolecular Immunology
Volume45
Issue number12
DOIs
StatePublished - Jul 2008

Funding

FundersFunder number
Hermann Minkowski-MINERVA Center for Geometry
Israeli Ministry of ScienceIST-006413, 236/06
Wolfson Foundation
Israel Science Foundation1208/04
Tel Aviv University

    Keywords

    • Antibody
    • Antigen
    • Epitope
    • Surface

    Fingerprint

    Dive into the research topics of 'Computational characterization of B-cell epitopes'. Together they form a unique fingerprint.

    Cite this