title: Chemoproteomics demonstrates target engagement and exquisite selectivity of the clinical phosphodiesterase 10A inhibitor MP-10 in its native environment.
abstract: Phosphodiesterases (PDEs) regulate the levels of the second messengers cAMP and cGMP and are important drug targets. PDE10A is highly enriched in medium spiny neurons of the striatum and is an attractive drug target for the treatment of basal ganglia diseases like schizophrenia, Parkinson's disease, or Huntington's disease. Here we describe the design, synthesis, and application of a variety of chemical biology probes, based on the first clinically tested PDE10A inhibitor MP-10, which were used to characterize the chemoproteomic profile of the clinical candidate in its native environment. A clickable photoaffinity probe was used to measure target engagement of MP-10 and revealed differences between whole cell and membrane preparations. Moreover, our results illustrate the importance of the linker design in the creation of functional probes. Biotinylated affinity probes allowed identification of drug-interaction partners in rodent and human tissue and quantitative mass spectrometry analysis revealed highly specific binding of MP-10 to PDE10A with virtually no off-target binding. The profiling of PDE10A chemical biology probes described herein illustrates a strategy by which high affinity inhibitors can be converted into probes for determining selectivity and target engagement of drug candidates in complex biological matrices from native sources.
authors.affiliation: Neuroscience Research Unit, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139 ( United States ).
authors.forename: Jan-Philip
authors.initials: JP
authors.lastname: Schülke
authors.forename: Laura A
authors.initials: LA
authors.lastname: McAllister
authors.forename: Kieran F
authors.initials: KF
authors.lastname: Geoghegan
authors.forename: Vinod
authors.initials: V
authors.lastname: Parikh
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Chappie
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Verhoest
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Schmidt
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Johnson
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Brandon
mesh_terms: D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000187:drug effects* / Q000201:enzymology; D002846:Chromatography, Affinity; D003342:Corpus Striatum / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D018360:Crystallography, X-Ray; D006801:Humans; D008027:Light; D008958:Models, Molecular; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010726:Phosphodiesterase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000378:metabolism*; D055668:Photochemical Processes; D061251:Primary Cell Culture; D011485:Protein Binding; D011720:Pyrazoles / Q000737:chemistry* / Q000494:pharmacology; D011804:Quinolines / Q000737:chemistry* / Q000494:pharmacology; D051381:Rats
chemical_list: C545121:2-((4-(1-methyl-4-pyridin-4-yl-1H-pyrazol-3-yl)phenoxy)methyl)quinoline; D015335:Molecular Probes; D010726:Phosphodiesterase Inhibitors; D011720:Pyrazoles; D011804:Quinolines; C119843:PDE10A protein, human; D010727:Phosphoric Diester Hydrolases