title: Symmetrical gas-phase dissociation of noncovalent protein complexes via surface collisions.
abstract: Previous gas-phase dissociation experiments of protein-protein complexes have resulted in product ion distributions that are asymmetric by charge and mass, providing limited insight into the chemical nature of subunit organization and interaction. In these experiments, a symmetric charge distribution results from an "energy sudden" collision of protein-protein complexes with a surface, indicating that it may be possible to probe the suboligomeric structure of noncovalent complexes in the gas phase. It is proposed that energy sudden surface activation of cytochrome C homodimers results in dissociation without significant unfolding of one of the monomeric subunits. Previously proposed mechanisms for the dissociation of protein-protein complexes are discussed in the context of these results. These experiments demonstrate the potential to preserve the structural details of subunit interaction within a protein-protein complex and help elucidate the asymmetric nature of macromolecular dissociation in the gas phase.
authors.affiliation: Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Jones
authors.forename: Richard L
authors.initials: RL
authors.lastname: Beardsley
authors.forename: Asiri S
authors.initials: AS
authors.lastname: Galhena
authors.forename: Shai
authors.initials: S
authors.lastname: Dagan
authors.forename: Guilong
authors.initials: G
authors.lastname: Cheng
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Wysocki
mesh_terms: D045304:Cytochromes c / Q000737:chemistry*; D005740:Gases; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013816:Thermodynamics
chemical_list: D005740:Gases; D045304:Cytochromes c