Abstract
Glycinamide ribonucleotide transformylase (GAR Tfase) catalyzes the first of two formyl transfer steps in the de novo purine biosynthetic pathway that require folate cofactors. Herein we report the discovery of a potent, nonpolyglutamatable, and selective inhibitor of GAR Tfase. Compound 12, which possesses a tetrazole in place of the gamma-carboxylic acid in the l-glutamate subunit of the potent GAR Tfase inhibitor 1, was active in cellular-based functional assays exhibiting purine-sensitive cytotoxic activity (IC(50) = 40 nM, CCRF-CEM) and was selective for inhibition of rhGAR Tfase (K(i) = 130 nM). Notably, 12 was only 2.5-fold less potent than 1 in cellular assays and 4-fold less potent against rhGAR Tfase. Like 1, this functional activity of 12 in the cell-based assay benefits from and requires transport into the cell by the reduced folate carrier but, unlike 1, is independent of folyl polyglutamate synthase (FPGS) expression levels and polyglutamation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Aminobutyrates / chemical synthesis*
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Aminobutyrates / chemistry
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Aminobutyrates / pharmacology
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Antineoplastic Agents / chemical synthesis*
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Antineoplastic Agents / chemistry
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Antineoplastic Agents / pharmacology
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Cell Line, Tumor
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Drug Screening Assays, Antitumor
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Humans
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Peptide Synthases / metabolism
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Phosphoribosylglycinamide Formyltransferase / antagonists & inhibitors*
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Phosphoribosylglycinamide Formyltransferase / chemistry
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Polyglutamic Acid / metabolism
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Pyrimidinones / chemical synthesis*
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Pyrimidinones / chemistry
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Pyrimidinones / pharmacology
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Structure-Activity Relationship
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Substrate Specificity
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Tetrahydrofolates / chemistry
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Tetrazoles / chemical synthesis*
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Tetrazoles / chemistry
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Tetrazoles / pharmacology
Substances
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10-(trifluoroacetyl)-5,10-dideazaacyclic-5,6,7,8-tetrahydrofolic acid
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2-(4-(6-(2,4-diamino-6-oxo-1,6-dihydropyrimidin-5-yl)-1,1,1-trifluoro-2-oxohexan-3-yl)benzamido)-4-(1H-tetrazol-5-yl)butanoic acid
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Aminobutyrates
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Antineoplastic Agents
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Pyrimidinones
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Tetrahydrofolates
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Tetrazoles
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Polyglutamic Acid
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Phosphoribosylglycinamide Formyltransferase
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Peptide Synthases
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folylpolyglutamate synthetase