title: Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface.
abstract: Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl.
authors.affiliation: From the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637.
authors.forename: John
authors.initials: J
authors.lastname: Wojcik
authors.affiliation: Swiss Institute for Experimental Cancer Research, School of Life Sciences, École polytechnique fédérale de Lausanne, 1015 Lausanne, Switzerland, and.
authors.forename: Allan Joaquim
authors.initials: AJ
authors.lastname: Lamontanara
authors.affiliation: From the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Grabe
authors.affiliation: From the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637.
authors.forename: Akiko
authors.initials: A
authors.lastname: Koide
authors.affiliation: From the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637.
authors.forename: Louesa
authors.initials: L
authors.lastname: Akin
authors.affiliation: Swiss Institute for Experimental Cancer Research, School of Life Sciences, École polytechnique fédérale de Lausanne, 1015 Lausanne, Switzerland, and.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gerig
authors.affiliation: Swiss Institute for Experimental Cancer Research, School of Life Sciences, École polytechnique fédérale de Lausanne, 1015 Lausanne, Switzerland, and oliver.hantschel@epfl.ch.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hantschel
authors.affiliation: From the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, Shohei.Koide@nyumc.org.
authors.forename: Shohei
authors.initials: S
authors.lastname: Koide
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects / Q000276:immunology; D058846:Antibodies, Monoclonal, Murine-Derived / Q000737:chemistry* / Q000276:immunology / Q000494:pharmacology; D045744:Cell Line, Tumor; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018909:src Homology Domains
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; C581634:BCR-ABL1 fusion protein, human; D016044:Fusion Proteins, bcr-abl
keywords: ABL tyrosine kinase; FN3; PPI inhibitor; Src homology 2 domain (SH2 domain); enzyme inhibitor; protein engineering; protein-protein interaction; x-ray crystallography