Comparison of Non-Covalent Interactions between a Series of N-Phosphoryl Dipeptide or Methyl Esters and Cytochrome C by Electrospray Ionization Mass Spectrometry

Abstract

The non-covalent interaction between a series of N-phosphoryl dipeptides (or methyl esters) (DPP) and cytochrome C was studied by ESI-MS. The function of different groups in DPP and binding sites of protein were investigated. The results revealed that hydroxyl and aromatic ring in DPP were both important group for the interaction, and aromatic ring had double functions on the interaction. In addition, the molecular size, flexibility and steric hindrance showed obvious effects on the interaction, while, the chirality, sequence and length of carbon chains (changing 1−2C) of amino acid residue in DPP showed little effects on the interaction under the experimental conditions. The results provide some useful information and theoretical basis for the molecular design of peptide drugs.