ME-COMPLEX · Fundamental study of siderophore-metal complexes with electrospray ionization in-source activation ion mobility-mass spectrometry

The electrospray ionization with mass spectrometry detection (ESI-MS) has been widely used to study biomolecules, low molecular weight compounds, and noncovalent complexes. Ion mobility spectrometry (IMS), capable of separating ions with the same m/z but varying sizes and shapes in the gaseous phase, has been recently hyphenated with the ESI-MS to conduct fundamental and applied research. The overall objective of this proposal is to generate new knowledge on the biological function and chemical characteristics of siderophore-metal complexes (SMCs) under real conditions such as seawater and rhizosphere by harnessing in-source activation (ISA) and cutting-edge ESI-IM-MS technology. To this end, the experimental investigations will involve varying ESI parameters, such as ESI and ISA voltages and drying gas temperature, and solution conditions, e.g. pH, solvent type, ionic strength, and matrix, to investigate stability and competitivity, hydrolysis, hydrogen-deuterium exchange behavior, and fragmentation patterns of SMCs plus finding the binding site locations of siderophores to metal ions in SMCs. The proposed project will also include experimental and theoretical calculations of collision cross-section (CCS) values and thermodynamic studies via quantum-mechanical methods, i.e. density functional theory to rationalize the experimental observations. The obtained CCS values will allow us to derive additional structural and spatial information on the investigated SMCs. The proposed project is multidisciplinary in nature as it integrates analytical chemistry, soil/plant research, environmental science, physical chemistry, and quantum mechanics. Two-way knowledge transfer in this project ensures the transfer of the candidate's expertise in the areas of sample preparation, flow systems, and 3D-printing technology to the host institution and training of the candidate in advanced analytical chemistry techniques to enhance his employability and career development.