Sizing large proteins and protein complexes by electrospray ionization mass spectrometry and ion mobility

• DOI: 10.1016/j.jasms.2007.02.015
• Publication Date: 2007-04-17T11:17:27Z
• Authors: Catherine S. Kaddis; Shirley H. Lomeli; Sheng Yin; Beniam Berhane; Marcin I. Apostol; Valerie A. Kickho...; Leonard H. Rome; Joseph A. Loo
• Keywords: Ion-mobility spectrometry; Molecular mass

Mass spectrometry (MS) and ion mobility with electrospray ionization (ESI) have the capability to measure detect large noncovalent protein-ligand protein-protein complexes. Using an method of gas-phase electrophoretic molecular analysis (GEMMA), protein particles representing a range sizes can be separated by their in air. Highly charged produced from complex solution using manipulated produce singly ions, which quantified mobility. Results ESI-GEMMA our laboratory others were compared other experimental theoretically determined parameters, such as mass cryoelectron microscopy X-ray crystal structure dimensions. There is strong correlation between diameter GEMMA for complexes up 12 MDa, including 93 kDa enolase dimer, 480 ferritin 24-mer complex, 4.6 MDa cowpea chlorotic mottle virus (CCMV), 9 MVP-vault assembly. used differentiate number similarly sized vault that are composed different N-terminal tags on MVP subunit. The average effective density proteins studied was 0.6 g/cm(3). Moreover, there evidence collapse or become more compact gas phase absence water.