title: Identification of Trypanosoma brucei AdoMetDC Inhibitors Using a High-Throughput Mass Spectrometry-Based Assay.
abstract: Human African trypanosomiasis (HAT) is a fatal infectious disease caused by the eukaryotic pathogen Trypanosoma brucei (Tb). Available treatments are difficult to administer and have significant safety issues. S-Adenosylmethionine decarboxylase (AdoMetDC) is an essential enzyme in the parasite polyamine biosynthetic pathway. Previous attempts to develop TbAdoMetDC inhibitors into anti-HAT therapies failed due to poor brain exposure. Here, we describe a large screening campaign of two small-molecule libraries (∼400,000 compounds) employing a new high-throughput (∼7 s per sample) mass spectrometry-based assay for AdoMetDC activity. As a result of primary screening, followed by hit confirmation and validation, we identified 13 new classes of reversible TbAdoMetDC inhibitors with low-micromolar potency (IC50) against both TbAdoMetDC and T. brucei parasite cells. The majority of these compounds were >10-fold selective against the human enzyme. Importantly, compounds from four classes demonstrated high propensity to cross the blood-brain barrier in a cell monolayer assay. Biochemical analysis demonstrated that compounds from eight classes inhibited intracellular TbAdoMetDC in the parasite, although evidence for a secondary off-target component was also present. The discovery of several new TbAdoMetDC inhibitor chemotypes provides new hits for lead optimization programs aimed to deliver a novel treatment for HAT.
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Volkov
authors.forename: Casey C
authors.initials: CC
authors.lastname: Cosner
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Brockway
authors.affiliation: Genzyme Corp. (now Sanofi Genzyme) , 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States.
authors.forename: Martin
authors.initials: M
authors.lastname: Kramer
authors.affiliation: Genzyme Corp. (now Sanofi Genzyme) , 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Booker
authors.forename: Shihua
authors.initials: S
authors.lastname: Zhong
authors.forename: Ariel
authors.initials: A
authors.lastname: Ketcherside
authors.forename: Shuguang
authors.initials: S
authors.lastname: Wei
authors.forename: Jamie
authors.initials: J
authors.lastname: Longgood
authors.forename: Melissa
authors.initials: M
authors.lastname: McCoy
authors.affiliation: Scynexis, Inc. (now Avista Pharma Solutions) , 3501 Tricenter Boulevard, Suite C, Durham, North Carolina 27713, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Richardson
authors.affiliation: Scynexis, Inc. (now Avista Pharma Solutions) , 3501 Tricenter Boulevard, Suite C, Durham, North Carolina 27713, United States.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Wring
authors.affiliation: Scynexis, Inc. (now Avista Pharma Solutions) , 3501 Tricenter Boulevard, Suite C, Durham, North Carolina 27713, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Peel
authors.affiliation: Genzyme Corp. (now Sanofi Genzyme) , 153 Second Avenue, Waltham, Massachusetts 02451-1122, United States.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klinger
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Posner
authors.forename: Jef K
authors.initials: JK
authors.lastname: De Brabander
authors.forename: Margaret A
authors.identifier: 0000-0001-5250-5578
authors.initials: MA
authors.lastname: Phillips
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D015870:Gene Expression; D057166:High-Throughput Screening Assays; D006801:Humans; D007700:Kinetics; D061985:Madin Darby Canine Kidney Cells; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D008954:Models, Biological; D021261:Parasitic Sensitivity Tests; D010539:Permeability; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014344:Trypanocidal Agents / Q000737:chemistry / Q000494:pharmacology*; D014346:Trypanosoma brucei brucei / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development
chemical_list: D004791:Enzyme Inhibitors; D015800:Protozoan Proteins; D054852:Small Molecule Libraries; D014344:Trypanocidal Agents; D012437:Adenosylmethionine Decarboxylase
keywords: AdoMetDC; Trypanosoma brucei; high-throughput screening; human African trypanosomiasis; mass spectrometry