Analysis of Conformational Differences of Copper and Alkali Metal Complexes of Insulin Using Trapped Ion Mobility-Mass Spectrometry Technique

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Hacettepe Journal of Biology and Chemistry, vol.51, no.1, pp.113-124, 2023 (Peer-Reviewed Journal) identifier


Molecular recognition, protein folding, and formation of supramolecular structures that occur at the molecular level of biological processes are based on noncovalent interactions. Interactions between metal atoms and proteins are based on noncovalent interactions that underlie the mechanisms involved in many cellular processes. The activities of enzymes are highly dependent on the interactions of such protein groups with cofactors, substrates, metal ions, and other proteins. The compositions and binding stoichiometry of protein-metal complexes can be determined with high accuracy performing mass spectrometry (MS) analysis. The conformational features of protein-metal complexes can be studied additionally using a mass spectrometer with ion mobility spectrometry (IMS) capability. This study focuses the monitoring the differences in the conformational changes of insulin protein during the formation of its complex with copper and alkali metals using trapped ion mobility spectrometry – time-of-flight (TIMS–TOF) mass spectrometer instrument. The compaction of the insulin structure by the formation of the insulin-copper complexes in the gas phase was determined with TIMS-TOF-MS analyses. However, no change was observed in the insulin structure with the addition of H, Na, and K atoms as adducts at the same analysis conditions.