The Protein Inter-Chain Interacton (PICI) web server is designed and developed for depicting various interactions at the protein-protein binding interface. Upon given a pdb identifier or a structure coordinate file uploaded by the user, PICI identifies and calculates the interactions of a selected chain with other chains in the protein. It shows the interface interactions interactively with JSmol structure viewer, a sequence visualization tool, and an interaction matrix. This tool also generates a plain text file and a xml file of all the interaction data for the users to download.

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Enter a PDBid :    


Upload your pdb file :

To view an example click on sample button.

For presubmitted structures
Enter accession id :    

Types of interactions calculated
Hydrogen bonds Other interactions
Strong Weak Disulfide bond,
Hydrophobic interaction,
Electrostatic interaction,
Π-Π interaction,
Cation-Π interaction,
Anion-Π interaction,
Lone pair-Π interaction,
Non-bonded contacts
N-H···(O / N / S),
O-H···(O / N / S),
S-H···(O / N / S)
C-H···(O / N / S),
(N / O / S / C)-H···Π
Details of the interaction calculation has been explained in the help section.

  1. Histidine is considered as in neutral form.
  2. For NMR structures only the first model is taken into consideration.
  3. Water molecules and heteroatoms have been excluded from calculation.
  4. Time to calculate interactions between chains depends on
    ( i )  size of the protein
    ( ii ) internet speed.
  5. User submitted structures wil be kept on repository for 30 days.