一般社団法人
日本質量分析学会

第123回　関東談話会講演会

	Probing protein tertiary structure and interaction by mass spectrometry Siu-Kwan Newman Sze (Genomic Institute of Singapore)
	Protein-protein interactions mediate essentially all biological processes. A detailed understanding of these interactions is thus a major goal of modern biological chemistry. Three dimensional structures, obtained with either NMR and X-ray crystallography methods, have provided considerable insights into the mechanisms of proteins binding. However, these methods are low throughput, labour intensive, and require large amount of high purity sample. Mass spectrometry is emerging as a powerful alternative technique to study protein-protein interaction, protein folding and conformation with the aim to determine 3D structure by coupling with protein structure modeling computation. Mass spectrometry has been applied to study both gas and solution phase protein structures. Electron capture dissociation is an efficient protein backbone dissociation method without disrupting its tertiary structure. If protein fragments are held together by intramolecular non-covalent bond, then the product detected is (M+nH)(n-1)+. The application of this method to study gas phase protein ion conformation and folding will be discussed. For protein structure in solution, protein footprinting maps the solvent accessible protein surface by chemical modification in solution coupled with mass spectrometry detection of modified surface residues. It can also be used to examine protein-protein interaction in solution. We have developed a pulse method to produce extensive protein surface modification. Both top down and bottom up mass spectrometry approaches of protein analysis have been applied to map the modified amino acids on protein surface.