- 1,3-disubstituted-4-aminopyrazolo [3, 4-d] pyrimidines, a new class of potent inhibitors for phospholipase D
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Phospholipase D enzymes cleave lipid substrates to produce phosphatidic acid, an important precursor for many essential cellular molecules. Phospholipase D is a target to modulate cancer-cell invasiveness. This study reports synthesis of a new class of phospholipase D inhibitors based on 1,3-disubstituted-4-amino-pyrazolopyrimidine core structure. These molecules were synthesized and used to perform initial screening for the inhibition of purified bacterial phospholipase D, which is highly homologous to the human PLD1. Initially tested with the bacterial phospholipase D enzyme, then confirmed with the recombinant human PLD1 and PLD2 enzymes, the molecules presented here exhibited inhibition of phospholipase D activity (IC50) in the low-nanomolar to low-micromolar range with both monomeric substrate diC4PC and phospholipid vesicles and micelles. The data strongly indicate that these inhibitory molecules directly block enzyme/vesicle substrate binding. Preliminary activity studies using recombinant human phospholipase Ds in in vivo cell assays measuring both transphosphatidylation and head-group cleavage indicate inhibition in the mid- to low-nanomolar range for these potent inhibitory novel molecules in a physiological environment. This study reports synthesis of a new class of PLD inhibitors based on 1,3-disubstituted-4-amino-pyrazolopyrimidine core structure. These molecules exhibited inhibition of human recombinant PLD activity (IC 50) in the low-nanomolar to low-micromolar range with monomeric substrate diC4PC and phospholipid vesicles and micelles. Preliminary activity studies using recombinant human PLDs in in vivo cell assays measuring both transphosphatidylation and head-group cleavage indicates inhibition in the mid- to low-nanomolar range for these potent inhibitory novel molecules in a physiological environment.
- Kulkarni, Aditya,Quang, Phong,Curry, Victoriana,Keyes, Renee,Zhou, Weihong,Cho, Hyejin,Baffoe, Jonathan,T?r?k, Béla,Stieglitz, Kimberly
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p. 270 - 281
(2014/10/15)
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- Optimizing small molecule inhibitors of calcium-dependent protein kinase 1 to prevent infection by toxoplasma gondii
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Toxoplasma gondii is sensitive to bulky pyrazolo [3,4-d] pyrimidine (PP) inhibitors due to the presence of a Gly gatekeeper in the essential calcium dependent protein kinase 1 (CDPK1). Here we synthesized a number of new derivatives of 3-methyl-benzyl-PP (3-MB-PP, or 1). The potency of PP analogues in inhibiting CDPK1 enzyme activity in vitro (low nM IC50 values) and blocking parasite growth in host cell monolayers in vivo (low μM EC 50 values) were highly correlated and occurred in a CDPK1-specific manner. Chemical modification of the PP scaffold to increase half-life in the presence of microsomes in vitro led to identification of compounds with enhanced stability while retaining activity. Several of these more potent compounds were able to prevent lethal infection with T. gondii in the mouse model. Collectively, the strategies outlined here provide a route for development of more effective compounds for treatment of toxoplasmosis and perhaps related parasitic diseases.
- Lourido, Sebastian,Zhang, Chao,Lopez, Michael S.,Tang, Keliang,Barks, Jennifer,Wang, Qiuling,Wildman, Scott A.,Shokat, Kevan M.,Sibley, L. David
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p. 3068 - 3077
(2013/06/05)
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- Generation of monospecific nanomolar tyrosine kinase inhibitors via a chemical genetic approach
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Selective protein kinase inhibitors are highly sought after as tools for studying cellular signal transduction cascades, yet few have been discovered due to the highly conserved fold of kinase catalytic domains. Through a combination of small molecule syn
- Bishop, Anthony C.,Kung, Chi-Yun,Shah, Kavita,Witucki, Laurie,Shokat, Kevan M.,Liu, Yi
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p. 627 - 631
(2007/10/03)
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