title: Extended Gas-Phase Trapping Followed by Surface-Induced Dissociation of Noncovalent Protein Complexes.
abstract: Mass spectrometry has emerged as a useful tool in the study of proteins and protein complexes. It is of fundamental interest to explore how the structures of proteins and protein complexes are affected by the absence of solvent and how this alters with increasing time in the gas phase. Here we demonstrate that a range of protein and protein complexes can be confined within the Trap T-wave region of a modified Waters Synapt G2S instrument, including monomeric (β-lactoglobulin), dimeric (β-lactoglobulin and enolase), tetrameric (streptavidin, concanavalin A, and pyruvate kinase), and pentameric (C-reactive protein) complexes, ranging in size up to 237 kDa. We demonstrate that complexes can be confined within the Trap region for varying lengths of time over the range 1-60 s and with up to 86% trapping efficiency for 1 s trapping. Furthermore, using model systems, we show that these noncovalent complexes can also be fragmented by surface-induced dissociation (SID) following trapping. SID reveals similar dissociation patterns over all trapping times studied for unactivated protein complexes, suggesting that any conformational changes occurring over this time scale are insufficient to cause substantial differences in the SID spectra of these complexes. Intentional alteration of structure by cone activation produces a distinct SID spectrum, with the differences observed being conserved, in comparison to unactivated complex, after trapping. However, subtle differences in the SID spectra of the activated complex are also observed as a function of trapping time.
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States.|School of Chemistry, Manchester Institute of Biotechnology, University of Manchester , Manchester, M1 7DN, United Kingdom.
authors.forename: Sophie R
authors.initials: SR
authors.lastname: Harvey
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Yan
authors.affiliation: Waters Corporation , Altrincham Road, Wilmslow, SK9 4AX, United Kingdom.
authors.forename: Jeffery M
authors.initials: JM
authors.lastname: Brown
authors.affiliation: Waters Corporation , Altrincham Road, Wilmslow, SK9 4AX, United Kingdom.
authors.forename: Emmy
authors.initials: E
authors.lastname: Hoyes
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States.
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Wysocki
mesh_terms: D002097:C-Reactive Protein / Q000737:chemistry*; D003208:Concanavalin A / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D007782:Lactoglobulins / Q000737:chemistry*; D013058:Mass Spectrometry; D010751:Phosphopyruvate Hydratase / Q000737:chemistry* / Q000378:metabolism; D011770:Pyruvate Kinase / Q000737:chemistry* / Q000378:metabolism; D019809:Streptavidin / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005740:Gases; D007782:Lactoglobulins; D003208:Concanavalin A; D002097:C-Reactive Protein; D019809:Streptavidin; D011770:Pyruvate Kinase; D010751:Phosphopyruvate Hydratase