123rd General Meeting of the KCS

Type Symposium
Area Mass Spectrometry in Chemical Biology
Room No. Room 407+408
Time FRI 10:20-10:40
Code LIFE2-4
Subject Secondary Structural Study of Biomolecules and Their Assemblies Using IM-MS and Gas-Phase IR Spectroscopy
Authors Jongcheol Seo
Department of Chemistry, Pohang University of Science and Technology, Korea
Abstract Mass spectrometry has been a routine tool for identifying and analyzing various biological molecules. Most recently, the structural studies of peptides, proteins, and their assemblies using MS-based methods firstly came to light in the developments of native mass spectrometry using very soft nano-electrospray ionization and have been significantly extended by emerging ion mobility mass spectrometry. However, the key question in this field has been whether the structures of biomolecules and their assemblies can be actually determined by using mass spectrometry-based gas-phase methods. Furthermore, it is also not clear if the structural elements of biomolecules are conserved after transfer to the gas phase via ionization. A clarification of this problem is important since it would allow very sensitive native mass spectrometry to be used to address problems relevant to structural biology. We used a combination of ion mobility-mass spectrometry (IM-MS) and gas-phase infrared spectroscopy to investigate the structures of biomolecules from small metabolite to peptides and proteins. Firstly, the secondary and tertiary structure of proteins transferred from solution to the gas phase was investigated. The results show that for low charge states under gentle ionization conditions, aspects of the native secondary and tertiary structure can be conserved. Based on this result, we further investigated amyloidogenic peptide aggregates and succeeded the first direct seconday structural analysis of every individual amyloid intermediate from dimer up to dodecamer. These results clearly suggest that the ion mobility-mass spectrometry can be used to investigate the secondary structures of proteins, peptides, and their aggregates.
E-mail jongcheol.seo@postech.ac.kr