Structure-Based  ·  Human-Specific

Predict Epitope
Residues from
Structure

HAIRpred2 identifies antibody-interacting residues in human antigens using 3D structural features - RSA, physicochemical properties, and a pre-trained Random Forest model achieving AUC 0.78.

HAIRpred2 — antibody-interacting residues visualized in PyMOL
Antibody-interacting residues (red) visualized in PyMOL using HAIRpred2 output

Why HAIRpred2

Built for structural precision

Unlike sequence-based tools, HAIRpred2 uses 3D structural information for residue-level epitope prediction.

0.78
AUC (best model)
277
Ag-Ab complexes
0.73
Sensitivity
0.65
Specificity

Structure-Based Input

Accepts standard PDB files. Uses DSSP to compute Relative Solvent Accessibility (RSA) for each residue directly from 3D coordinates.

Human-Specific Model

Trained exclusively on 277 human Ag-Ab complexes from SAbDab — captures unique features of human immune recognition.

Hybrid Feature Set

15-residue sliding window encodes RSA + pI, pKa, hydrophobicity, steric, and EIIP — 105 features per residue.

Epitope Patch Detection

Clusters spatially adjacent interacting residues (Cα < 10Å) into epitope patches — regions antibodies actually bind.

PyMOL-Ready Output

Generates a .pml script for direct PyMOL loading — red/blue coloring with probability labels on every interacting residue.

Standalone Available

Download Python standalone for local use. Supports multiple chains, RSA filtering, and custom probability thresholds.


Output Files

Five outputs per job

Every prediction generates a complete set of files for downstream analysis and visualization.

.csv

Prediction Table

Per-residue: Residue, RSA, Probability, Interacting/Non-interacting label.

_summary.txt

Statistics Report

Counts, percentages, average probability, and top 10 highest-scoring residues.

_bfactor.pdb

B-Factor PDB

Probability in B-factor column. PyMOL: spectrum b, blue_white_red

.pml

PyMOL Script

Auto-colors red/blue with probability labels on Cα atoms of interacting residues.

_patches.txt

Epitope Patches

Spatially clustered interacting residues with average patch probability scores.

Run Prediction

Upload a PDB to get all 5 output files


Citation

How to cite

HAIRpred2: Mehta N., et al. (2025) HAIRpred2: Structure-based prediction of antibody-interacting residues in human antigens. (manuscript in preparation)

HAIRpred (previous): Sahni R., Kumar N. and Raghava GPS (2025) HAIRpred: Prediction of human antibody interacting residues in an antigen from its primary structure. Protein Sci, 34(8):e70212