title: Use of hydrogen/deuterium exchange mass spectrometry and mutagenesis as a tool to identify the binding region of inhibitors targeting the human mitotic kinesin Eg5.
abstract: An experimental procedure associating both hydrogen/deuterium exchange mass spectrometry (H/D-MS) and mutagenesis was developed to identify the protein-binding region of small inhibitors targeting the motor domain of the human mitotic kinesin Eg5. All the tested inhibitors decrease the deuterium incorporation rate of the same peptides corresponding to the following secondary structure elements: loop L5/helix alpha2 (region Tyr125-Glu145) and strand beta5/helix alpha3 (region Ile202-Leu227). Replacement of these two regions by the equivalent ones from N. crassa conventional kinesin heavy chain completely abolishes the modification of the deuterium incorporation rate by the inhibitors as well as their effects on the basal ATPase activity. The six tested inhibitors thus share a common binding site on Eg5. The strategy reported here allows the regions of a protein involved in ligand binding to be rapidly pinpointed and can be applied to other proteins and used as a general in vitro screening procedure to identify compounds targeting specific binding regions.
authors.affiliation: Laboratoire de Spectrométrie de Masse des Protéines (LSMP), Institut de Biologie Structurale (CEA-CNRS-UJF), 41, rue Jules Horowitz, 38027 Grenoble Cedex 01, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Brier
authors.forename: David
authors.initials: D
authors.lastname: Lemaire
authors.forename: Salvatore
authors.initials: S
authors.lastname: DeBonis
authors.forename: Frank
authors.initials: F
authors.lastname: Kozielski
authors.forename: Eric
authors.initials: E
authors.lastname: Forest
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D041961:Deuterium Exchange Measurement / Q000379:methods*; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D016547:Kinesins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007700:Kinetics; D008938:Mitosis; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016296:Mutagenesis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D004791:Enzyme Inhibitors; C470243:KIF11 protein, human; D016547:Kinesins