Abstract
We have explored the roles played by C-H…π hydrogen bonds in interleukins. Main-chain to side-chain C-H…π interactions are the predominant type of interactions in interleukins. There was an average of 15 C-H…π interactions per protein and also there was an average of one significant C-H…π interaction for every 14 residues in the interleukins investigated. Significant contribution to C-H…π interactions was only from Asp, Gly, His, Lys, Phe, Pro, Ser, Thr, Trp and Tyr in interleukins. Trp contributed both donor and acceptor atoms in main-chain to side-chain, main-chain to side-chain 5 member aromatic ring and side-chain to side-chain C-H…π interactions. Short and medium-range C-H…π interactions are the predominant type of interactions in interleukins. More than 50% of C-H…π interacting residues had a conservation score of ⩾ 6. Significant percentage of C-H…π interacting residues had one or more stabilization centers; hence these residues may also contribute additional stability to structure of interleukins.