Proteomic Strategies For Investigation Of Protein/ligand And Peptide/ligand Non-covalent Interactions By Electrospray Ionization Mass Spectrometry

Abstract

Through universal proteomic methods and electrospray ionization-mass spectrometry (ESI-MS), multiple molecular recognition strategies were investigated as a prospective complementary tool for investigating protein-ligand interactions. Three model protein-ligand systems: bovine serum albumin/naproxen, cytochrome c/ATP & ADP, and integrin/RGD peptide were probed based on the categorical difference in the nature of each ligand. It was found that screening for protein binding sites from proteolytic digests was feasible for one of three models. Three different proteolytic digests of cytochrome c featured several examples of binding interaction with the ligands ATP and ADP. The detection of binding between intact cytochrome c and ATP/ADP was also conducted. Both the folded and unfolded state of cytochrome c were observed under ESI-MS conditions with ATP/ADP binding to the native states. Dissociation constants calculated for intact cytochrome c and ATP/ADP and the results were in correlation with existing literature.