title: Enhanced correction methods for hydrogen exchange-mass spectrometric studies of amyloid fibrils.
abstract: We describe methods for minimization of and correction for artifactual forward and backward exchange occurring during hydrogen exchange-mass spectrometric (HX-MS) studies of amyloid fibrils of the Abeta(1-40) peptide. The quality of the corrected data obtained using published and new correction algorithms is evaluated quantitatively. Using the new correction methods, we have determined that 20.1 +/- 1.4 of the 39 backbone amide hydrogens in Abeta(1-40) exchange with deuteriums in 100 h when amyloid fibrils of this peptide are suspended in D(2)O. These data reinforce our previous conclusions based on uncorrected data that amyloid fibrils contain a rigid protective core structure that involves only about half of the Abeta backbone amides. The methods developed here should be of general value for HX-MS studies of amyloid fibrils and other protein aggregates.
authors.affiliation: Graduate School of Medicine, University of Tennessee Medical Center, University of Tennessee, Knoxville, Tennessee 37996-1600, USA.
authors.forename: Indu
authors.initials: I
authors.lastname: Kheterpal
authors.forename: Ronald
authors.initials: R
authors.lastname: Wetzel
authors.forename: Kelsey D
authors.initials: KD
authors.lastname: Cook
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D006801:Humans; D006859:Hydrogen / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D006859:Hydrogen