Distribution of tripeptides in MHC binding peptides.

Major Histocompatibility Complex (MHC) molecules are cell surface glycoproteins that are central to the process of immunity. MHC Class I and II molecules differ in their peptide binding specificity. In this study we have analyzed a non redundant set of MHC binding peptides derived from MHCPEP database, in terms of tripeptides and their positional preference. Results indicate that certain tripeptides have a preference to appear at a particular position for a specific allele. Further, the distribution of rigid tripeptides across all binding sequences was also analyzed and their positions were correlated with anchor residue positions.