title: Binding interface of cardiac potassium channel proteins identified by hydrogen deuterium exchange of synthetic peptides.
abstract: Three synthetic peptides, derived from the human potassium channel proteins Ether-a-go-go-related gene (HERG), KCNQ1, and KCNE1, were investigated by hydrogen deuterium exchange coupled with electron-transfer dissociation mass spectrometry at single residue resolution. Each amino acid residue in the first half of the HERG peptide incorporated deuterons with a higher rate than those in the second half of the peptide, consistent with the nuclear magnetic resonance structure of this peptide, with amino acids 1-10 being a flexible coil, whereas amino acids 11-24 are a stable amphipathic helix. The binding interface of KCNQ1 and KCNE1 was determined by comparing the difference of sequential fragment ions before and after binding. The residues determined to be involved in binding were consistent with a cysteine cross-linking study and confirmed by double mutant cycle analysis.
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: Jerri
authors.initials: J
authors.lastname: Chen
authors.forename: Ruth
authors.initials: R
authors.lastname: Angeletti
authors.forename: Thomas V
authors.initials: TV
authors.lastname: McDonald
authors.forename: Hui
authors.initials: H
authors.lastname: Xiao
mesh_terms: D000595:Amino Acid Sequence; D003903:Deuterium / Q000737:chemistry; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding
chemical_list: C489622:KCNE1 protein, human; D051657:KCNQ1 Potassium Channel; D010455:Peptides; D024642:Potassium Channels, Voltage-Gated; D003903:Deuterium