Dihydrofolate reductase inhibitors as potential drugs

McCormack, John J.

doi:10.1002/med.2610010305

Cited by 15 publications

(4 citation statements)

References 138 publications

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“…Inhibition of dihydrofolate reductase by antifolate drugs is important in the chemotherapeutic treatment of several diseases (McCormack, 1981;Roth & Cheng, 1982). Consequently, the mechanism of this inhibition has been studied extensively (McCormack, 1981;Roth & Cheng, 1982; Gready, 1980;Hitchings & Smith, 1980). Fewer investigations have dealt with the kinetic mechanism of the enzyme-catalyzed reaction.…”

mentioning

confidence: 99%

Dihydrofolate reductase from Escherichia coli: the kinetic mechanism with NADPH and reduced acetylpyridine adenine dinucleotide phosphate as substrates

Stone¹,

Morrison²

1988

Biochemistry

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Kinetic studies on the reaction catalyzed by dihydrofolate reductase from Escherichia coli have been undertaken with the aim of characterizing further the kinetic mechanism of the reaction. For this purpose, the kinetic properties of substrates were determined by measurement of (a) initial velocities over a wide range of substrate concentrations and (b) the stickiness of substrates in ternary enzyme complexes. Stickiness is defined as the rate at which a substrate reacts to give products relative to the rate at which that substrate dissociates. Stickiness was determined by varying the viscosity of reaction mixtures and the concentration of one substrate in the presence of a saturating concentration of the other substrate. The results indicate that NADPH is sticky in the enzyme-NADPH-dihydrofolate complex, while dihydrofolate is much less sticky in this complex. At higher concentrations, NADPH functions as an activator through the formation of an enzyme-NADPH-tetrahydrofolate from which tetrahydrofolate is released more rapidly than from an enzyme-tetrahydrofolate complex. Higher concentrations of dihydrofolate also cause enzyme activation, and it appears that this effect is due to the ability of dihydrofolate to displace tetrahydrofolate from a binary enzyme complex through the formation of a transitory enzyme-tetrahydrofolate-dihydrofolate complex. As NADPH and dihydrofolate function as activators and as NADPH behaves as a sticky substrate, the kinetic mechanism of the dihydrofolate reductase reaction with the natural substrates is steady-state random. By contrast with NADPH, reduced 3-acetylpyridine adenine dinucleotide phosphate exhibits only slight stickiness and does not function as an activator.(ABSTRACT TRUNCATED AT 250 WORDS)

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confidence: 99%

Dihydrofolate reductase from Escherichia coli: the kinetic mechanism with NADPH and reduced acetylpyridine adenine dinucleotide phosphate as substrates

Stone¹,

Morrison²

1988

Biochemistry

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“…35,40 Likewise, NSC7364 is commonly known as metoprine and is also a known inhibitor of DHFR from various sources. 41 Prediction of the above two molecules serves as an internal quality control of the VS algorithm's predictive ability and reinforces our confidence in the novel ligands that are predicted. The sole novel hit from this class, NSC71669, with two trifluoromethyl phenyl substituents on a Indicates reported inhibitors of DHFR independently picked up by PoLi and validated experimentally.…”

Section: Journal Of Chemical Information and Modelingmentioning

confidence: 61%

“…NSC740, commonly known as methotrexate, is a well-known DHFR inhibitor acting on both prokaryotic and eukaryotic homologs 35, 40 . Likewise, NSC7364 is commonly known as metoprine and is also a known inhibitor of DHFR from various sources 41 . Prediction of the above two molecules serves as an internal quality control of the VS algorithm's predictive ability and reinforces our confidence in the novel ligands that are predicted.…”

Section: Resultsmentioning

confidence: 99%

PoLi: A Virtual Screening Pipeline Based on Template Pocket and Ligand Similarity

Roy

Srinivasan

Skolnick

2015

J. Chem. Inf. Model.

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Often in pharmaceutical research, the goal is to identify small molecules that can interact with and appropriately modify the biological behavior of a new protein target. Unfortunately, most proteins lack both known structures and small molecule binders, prerequisites of many virtual screening, VS, approaches. For such proteins, ligand homology modeling, LHM, that copies ligands from homologous and perhaps evolutionarily distant template proteins, has been shown to be a powerful VS approach to identify possible binding ligands. However, if we want to target a specific pocket for which there is no homologous holo template protein structure, then LHM will not work. To address this issue, in a new pocket based approach, PoLi, we generalize LHM by exploiting the fact that the number of distinct small molecule ligand binding pockets in proteins is small. PoLi identifies similar ligand binding pockets in a holo-template protein library, selectively copies relevant parts of template ligands and uses them for VS. In practice, PoLi is a hybrid structure and ligand based VS algorithm that integrates 2D fingerprint-based and 3D shape-based similarity metrics for improved virtual screening performance. On standard DUD and DUD-E benchmark databases, using modeled receptor structures, PoLi achieves an average enrichment factor of 13.4 and 9.6 respectively, in the top 1% of the screened library. In contrast, traditional docking based VS using AutoDock Vina and homology-based VS using FINDSITEfilt have an average enrichment of 1.6 (3.0) and 9.0 (7.9) on the DUD (DUD-E) sets respectively. Experimental validation of PoLi predictions on dihydrofolate reductase, DHFR, using differential scanning fluorimetry, DSF, identifies multiple ligands with diverse molecular scaffolds, thus demonstrating the advantage of PoLi over current state-of-the-art VS methods.

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“…The enzyme dihydrofolate reductase (DHFR) is an example of a protein target where drug development has yielded clinically used compounds with varying specificities for certain cell types. , Methotrexate (Mtx) is an example of a drug that inhibits bacterial DHFRs, but also inhibits human DHFR and therefore is too toxic to be used as an antibacterial. The cytotoxic effects of Mtx against human cells permits its use as an antineoplastic agent.…”

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confidence: 99%

Maximizing the Therapeutic Window of an Antimicrobial Drug by Imparting Mitochondrial Sequestration in Human Cells

Pereira

2011

J. Am. Chem. Soc.

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The number of antimicrobial agents available for use in humans is limited by the difficulty of discovering chemical agents with selective toxicity to bacterial targets. Numerous small molecule inhibitors have potential as antimicrobial agents, yet their use has been prevented by high levels of toxic cross-reactivity in human cells. For example, methotrexate (Mtx) is an effective antimetabolite that exerts its effects by inhibiting DHFR. It is a potent antibacterial when accumulated intracellularly, but toxicity in human cells limits clinical utility in infectious disease treatment. Here, we describe peptide conjugates of Mtx that are sequestered into the mitochondria of human cells (mt-Mtx). This alteration in localization of Mtx, which directs it away from its enzyme target, decreases its toxicity in human cells by a factor of 10(3). Mt-Mtx, however, maintains activity against a variety of pathogenic gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). The results from this proof-of-principle study describe a novel methodology for augmenting the antibacterial efficacy of drugs amenable to peptide conjugation while simultaneously decreasing their toxicity to the host organism.

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Dihydrofolate reductase inhibitors as potential drugs

Cited by 15 publications

References 138 publications

Dihydrofolate reductase from Escherichia coli: the kinetic mechanism with NADPH and reduced acetylpyridine adenine dinucleotide phosphate as substrates

Dihydrofolate reductase from Escherichia coli: the kinetic mechanism with NADPH and reduced acetylpyridine adenine dinucleotide phosphate as substrates

PoLi: A Virtual Screening Pipeline Based on Template Pocket and Ligand Similarity

Maximizing the Therapeutic Window of an Antimicrobial Drug by Imparting Mitochondrial Sequestration in Human Cells

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