Surface Plasmon Resonance coupled to Mass Spectrometry to studylectin-sugar interactions

Abstract

International audienceBiomolecular interactions are at the heart of the functioning of all living systems. The study ofbiointeractions is essential for understanding the global organization of the cellular machinery and theirrole in physiological processes. They constitute a significant challenge in analytical chemistry,diagnostics, and therapeutic research.Lectins are proteins that specifically recognize edible sugars. Our project aims to develop a couplingbetween Surface Plasmon Resonance Imaging and Mass Spectrometry (SPRi -MS) to analyze protein-sugar interactions. The aim is to create a multiplex SPR biochip with immobilized lectins and then to usethis biochip in coupling with MALDI-TOF-MS. This coupling allows the kinetics and thermodynamics ofthe interaction to be studied in real-time, together with the structural identification of the sugarscaptured from a complex mixture.By SPRi, this work confirmed significant interactions, between the lectin WGA and the neoglycosylatedBSA gratied carrying the sugars N-acetylgalactosamine and N-acetylglucosamine, and between the lectinAIA and neoglycosylated BSA carrying galactose and its N-acetylated form. We atempted the MSdetection of captured glycosylated BSA directly from the biochip surface; however, the lack of sensitivityin MS detection hindered the development of the coupling. The sensitivity depends, on the amount ofligands retained on biochip surface, which itself depends, among other factors, on the chemicalfunctionalization of the biochip surface, the nature of the receptors and their immobilization on thesurface [1]. Modifications of the MALDI-TOF-MS analysis conditions are being carried out with the useof MALDI imaging and the use of alternative receptors in order to evaluate their impact on the sensitivityof detection by SPRi-MS