Welcome to the ISPRED4 prediction server

Please note:


Due to a scheduled power outage, our website will be temporarily unavailable from March 26 to March 28, 2025. We kindly ask you to complete any pending jobs by March 25, 2025. We apologize for the inconvenience and appreciate your understanding.

ISPRED4 (Interaction Site PREDictor version 4) is a web-server for predicting protein-protein interaction sites starting from protein structure. ISPRED4 adopts machine-learning methods (SVM+CRF) to predict interaction state of each residue in the protein surface by extracting several features from protein sequence and structure.

Submit a PDB file

To start using ISPRED4 you simply need to upload a protein 3D structure in PDB format and specify the protein chain you want to analyze. You can also specificy a RSA threshold to select surface residues (all residues with RSA above the threshold are considered surface residues. Default value is: 0.20). Therefore, press the "Start prediciton" button to submit your job. The server accepts in input a single protein structure.