title: Top down proteomics of human membrane proteins from enriched mitochondrial fractions.
abstract: The interrogation of intact integral membrane proteins has long been a challenge for biological mass spectrometry. Here, we demonstrate the application of top down mass spectrometry to whole membrane proteins below 60 kDa with up to 8 transmembrane helices. Analysis of enriched mitochondrial membrane preparations from human cells yielded identification of 83 integral membrane proteins, along with 163 membrane-associated or soluble proteins, with a median q value of 3 × 10(-10). An analysis of matching fragment ions demonstrated that significantly more fragment ions were found within transmembrane domains than would be expected based upon the observed protein sequence. In total, 46 proteins from the complexes of oxidative phosphorylation were identified which exemplifies the increasing ability of top down proteomics to provide extensive coverage in a biological network.
authors.affiliation: Department of Chemistry, the Chemistry of Life Processes Institute, and the Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, Illinois, 60208, United States.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Catherman
authors.forename: Mingxi
authors.initials: M
authors.lastname: Li
authors.forename: John C
authors.initials: JC
authors.lastname: Tran
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Durbin
authors.forename: Philip D
authors.initials: PD
authors.lastname: Compton
authors.forename: Bryan P
authors.initials: BP
authors.lastname: Early
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thomas
authors.forename: Neil L
authors.initials: NL
authors.lastname: Kelleher
mesh_terms: D000595:Amino Acid Sequence; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics*; D008928:Mitochondria / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D040901:Proteomics / Q000379:methods*
chemical_list: D008565:Membrane Proteins