Deciphering Interactions Involved in Immobilized Metal Ion Affinity Chromatography and Surface Plasmon Resonance for Validating the Analogy between Both Technologies

Various peptides can be obtained through protein enzymatic hydrolysis. Immobilized metal ion affinity chromatography (IMAC) is one of the methods which can be used to separate metal chelating peptides (MCPs) in a hydrolysate mixture. In this context, this work aims to understand deeply the interactions in IMAC and surface plasmon resonance (SPR) in order to validate experimentally the analogy between both technologies and to be further able to perform IMAC modeling in the next work using peptide sorption isotherm parameters obtained from SPR. Indeed, chromatography modeling can be used to predict separation of MCPs in IMAC and the knowledge of peptide sorption isotherm obtained from SPR is a crucial step. For this purpose, 22 peptides were selected and investigated in IMAC using HisTrap X-Ni2+ and HiFliQ NTA-Ni2+ columns and were also studied in SPR as well. Results showed that peptides with histidine residues had good affinity to Ni2+, while the high positive charge of peptides was responsible of ionic interactions. Further, most of the peptides with good retention time in IMAC showed a good affinity in SPR as well, which validated experimentally the SPR-IMAC analogy.