New Mutation in ParE in a Pneumococcal In Vitro Mutant Resistant to Fluoroquinolones

ABSTRACT In Streptococcus pneumoniae, an H103Y substitution in the ATP binding site of the ParE subunit of topoisomerase IV was shown to confer quinolone resistance and hypersensitivity to novobiocin when associated with an S84F change in the A subunit of DNA gyrase. We reconstituted in vitro the wild-type topoisomerase IV and its ParE mutant. The ParE mutant enzyme showed a decreased activity for decatenation at subsaturating ATP levels and was more sensitive to inhibition by novobiocin but was as sensitive to quinolones. These results show that the ParE alteration H103Y alone is not responsible for quinolone resistance and agree with the assumption that it facilitates the open conformation of the ATP binding site that would lead to novobiocin hypersensitivity and to a higher requirement of ATP.

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ATP-Bound Conformation of Topoisomerase IV: a Possible Target for Quinolones in Streptococcus pneumoniae

Journal of Bacteriology ◽

10.1128/jb.185.20.6137-6146.2003 ◽

2003 ◽

Vol 185 (20) ◽

pp. 6137-6146 ◽

Cited By ~ 7

Author(s):

Farid Sifaoui ◽

Valérie Lamour ◽

Emmanuelle Varon ◽

Dino Moras ◽

Laurent Gutmann

Keyword(s):

Streptococcus Pneumoniae ◽

Binding Site ◽

Active Site ◽

Random Mutagenesis ◽

Bacterial Pathogen ◽

Quinolone Resistance ◽

Atp Binding ◽

Topoisomerase Iv ◽

Atp Binding Site ◽

Dimeric Interface

ABSTRACT Topoisomerase IV, a C2E2 tetramer, is involved in the topological changes of DNA during replication. This enzyme is the target of antibacterial compounds, such as the coumarins, which target the ATP binding site in the ParE subunit, and the quinolones, which bind, outside the active site, to the quinolone resistance-determining region (QRDR). After site-directed and random mutagenesis, we found some mutations in the ATP binding site of ParE near the dimeric interface and outside the QRDR that conferred quinolone resistance to Streptococcus pneumoniae, a bacterial pathogen. Modeling of the N-terminal, 43-kDa ParE domain of S. pneumoniae revealed that the most frequent mutations affected conserved residues, among them His43 and His103, which are involved in the hydrogen bond network supporting ATP hydrolysis, and Met31, at the dimeric interface. All mutants showed a particular phenotype of resistance to fluoroquinolones and an increase in susceptibility to novobiocin. All mutations in ParE resulted in resistance only when associated with a mutation in the QRDR of the GyrA subunit. Our models of the closed and open conformations of the active site indicate that quinolones preferentially target topoisomerase IV of S. pneumoniae in its ATP-bound closed conformation.

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New Mechanistic Insight on the PIM-1 Kinase Inhibitor AZD1208 Using Multidrug Resistant Human Erythroleukemia Cell Lines and Molecular Docking Simulations

Current Topics in Medicinal Chemistry ◽

10.2174/1568026619666190509121606 ◽

2019 ◽

Vol 19 (11) ◽

pp. 914-926 ◽

Cited By ~ 2

Author(s):

Maiara Bernardes Marques ◽

Michael González-Durruthy ◽

Bruna Félix da Silva Nornberg ◽

Bruno Rodrigues Oliveira ◽

Daniela Volcan Almeida ◽

...

Keyword(s):

Molecular Docking ◽

Binding Site ◽

Cell Lines ◽

Chemotherapeutic Agents ◽

Atp Binding ◽

Human Leukemia ◽

Atp Binding Site ◽

Mechanistic Insight ◽

Multiple Drugs

Background:PIM-1 is a kinase which has been related to the oncogenic processes like cell survival, proliferation, and multidrug resistance (MDR). This kinase is known for its ability to phosphorylate the main extrusion pump (ABCB1) related to the MDR phenotype.Objective:In the present work, we tested a new mechanistic insight on the AZD1208 (PIM-1 specific inhibitor) under interaction with chemotherapy agents such as Daunorubicin (DNR) and Vincristine (VCR).Materials and Methods:In order to verify a potential cytotoxic effect based on pharmacological synergism, two MDR cell lines were used: Lucena (resistant to VCR) and FEPS (resistant to DNR), both derived from the K562 non-MDR cell line, by MTT analyses. The activity of Pgp was ascertained by measuring accumulation and the directional flux of Rh123. Furthermore, we performed a molecular docking simulation to delve into the molecular mechanism of PIM-1 alone, and combined with chemotherapeutic agents (VCR and DNR).Results:Our in vitro results have shown that AZD1208 alone decreases cell viability of MDR cells. However, co-exposure of AZD1208 and DNR or VCR reverses this effect. When we analyzed the ABCB1 activity AZD1208 alone was not able to affect the pump extrusion. Differently, co-exposure of AZD1208 and DNR or VCR impaired ABCB1 activity, which could be explained by compensatory expression of abcb1 or other extrusion pumps not analyzed here. Docking analysis showed that AZD1208 is capable of performing hydrophobic interactions with PIM-1 ATP- binding-site residues with stronger interaction-based negative free energy (FEB, kcal/mol) than the ATP itself, mimicking an ATP-competitive inhibitory pattern of interaction. On the same way, VCR and DNR may theoretically interact at the same biophysical environment of AZD1208 and also compete with ATP by the PIM-1 active site. These evidences suggest that AZD1208 may induce pharmacodynamic interaction with VCR and DNR, weakening its cytotoxic potential in the ATP-binding site from PIM-1 observed in the in vitro experiments.Conclusion:Finally, the current results could have a pre-clinical relevance potential in the rational polypharmacology strategies to prevent multiple-drugs resistance in human leukemia cancer therapy.

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Engineering the Specificity of Antibacterial Fluoroquinolones: Benzenesulfonamide Modifications at C-7 of Ciprofloxacin Change Its Primary Target in Streptococcus pneumoniae from Topoisomerase IV to Gyrase

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.2.320-325.2000 ◽

2000 ◽

Vol 44 (2) ◽

pp. 320-325 ◽

Cited By ~ 74

Author(s):

Fabiana L. Alovero ◽

Xiao-Su Pan ◽

Julia E. Morris ◽

Ruben H. Manzo ◽

L. Mark Fisher

Keyword(s):

Streptococcus Pneumoniae ◽

Resistance Mutation ◽

Dna Supercoiling ◽

Quinolone Resistance ◽

Primary Target ◽

Topoisomerase Iv ◽

Enhanced Activity

ABSTRACT We have examined the antipneumococcal mechanisms of a series of novel fluoroquinolones that are identical to ciprofloxacin except for the addition of a benzenesulfonylamido group to the C-7 piperazinyl ring. A number of these derivatives displayed enhanced activity againstStreptococcus pneumoniae strain 7785, including compound NSFQ-105, bearing a 4-(4-aminophenylsulfonyl)-1-piperazinyl group at C-7, which exhibited an MIC of 0.06 to 0.125 μg/ml compared with a ciprofloxacin MIC of 1 μg/ml. Several complementary approaches established that unlike the case for ciprofloxacin (which targets topoisomerase IV), the increased potency of NSFQ-105 was associated with a target preference for gyrase: (i) parC mutants of strain 7785 that were resistant to ciprofloxacin remained susceptible to NSFQ-105, whereas by contrast, mutants bearing a quinolone resistance mutation in gyrA were four- to eightfold more resistant to NSFQ-105 (MIC of 0.5 μg/ml) but susceptible to ciprofloxacin; (ii) NSFQ-105 selected first-step gyrAmutants (MICs of 0.5 μg/ml) encoding Ser-81-to-Phe or -Tyr mutations, whereas ciprofloxacin selects parC mutants; and (iii) NSFQ-105 was at least eightfold more effective than ciprofloxacin at inhibiting DNA supercoiling by S. pneumoniae gyrase in vitro but was fourfold less active against topoisomerase IV. These data show unequivocally that the C-7 substituent determines not only the potency but also the target preference of fluoroquinolones. The importance of the C-7 substituent in drug-enzyme contacts demonstrated here supports one key postulate of the Shen model of quinolone action.

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STRUCTURE-ACTIVITY RELATIONSHIPS FOR 4-ANILINOQUINAZOLINES AS POTENT INHIBITORS AT THE ATP BINDING SITE OF THE EPIDERMAL GROWTH FACTOR RECEPTOR IN VITRO

Clinical and Experimental Pharmacology and Physiology ◽

10.1111/j.1440-1681.1996.tb02752.x ◽

1996 ◽

Vol 23 (5) ◽

pp. 424-427 ◽

Cited By ~ 19

Author(s):

William A Denny ◽

Gordon W Rewcastle ◽

Alexander J Bridges ◽

David W Fry ◽

Alan J Kraker

Keyword(s):

Epidermal Growth Factor Receptor ◽

Growth Factor ◽

Epidermal Growth Factor ◽

Binding Site ◽

Growth Factor Receptor ◽

Atp Binding ◽

Atp Binding Site ◽

Structure Activity ◽

Epidermal Growth

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A mutation at the ATP-binding site of pp60v-src abolishes kinase activity, transformation, and tumorigenicity

Molecular and Cellular Biology ◽

10.1128/mcb.5.7.1772-1779.1985 ◽

1985 ◽

Vol 5 (7) ◽

pp. 1772-1779

Author(s):

M A Snyder ◽

J M Bishop ◽

J P McGrath ◽

A D Levinson

Keyword(s):

Binding Site ◽

Kinase Activity ◽

Atp Binding ◽

Wild Type ◽

Dependent Protein Kinase ◽

Atp Binding Site ◽

Specific Immunoglobulin ◽

Dependent Protein ◽

Infected Cells

We constructed a mutant, called RSV-SF2, at the ATP-binding site of pp60v-src. In this mutant, lysine-295 is replaced with methionine. SF2 pp60v-src was found to have a half-life similar to that of wild-type pp60v-src and was localized in the membranous fraction of the cell. Rat cells expressing SF2 pp60v-src were morphologically untransformed and do not form tumors. The SF2 pp60v-src isolated from these cells lacked kinase activity with either specific immunoglobulin or other substrates, and expression of SF2 pp60v-src failed to cause an increase of total phosphotyrosine in the proteins of infected cells. Wild-type pp60v-src was phosphorylated on serine and tyrosine in infected cells, and the analogous phosphorylations could also be carried out in vitro. Phosphorylation of serine was catalyzed by a cyclic AMP-dependent protein kinase, and phosphorylation of tyrosine was perhaps catalyzed by pp60v-src itself. By contrast, SF2 pp60v-src could not be phosphorylated on serine or tyrosine either in infected cells or in vitro. These findings strengthen the belief that the phosphotransferase activity of pp60v-src is required for neoplastic transformation by the protein and suggest that the binding of ATP to pp60v-src elicits an allosteric change required for phosphorylation of serine in the protein.

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In Vitro Activities of Novel Nonfluorinated Quinolones PGE 9262932 and PGE 9509924 against Clinical Isolates of Staphylococcus aureus and Streptococcus pneumoniae with Defined Mutations in DNA Gyrase and Topoisomerase IV

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.6.1651-1657.2002 ◽

2002 ◽

Vol 46 (6) ◽

pp. 1651-1657 ◽

Cited By ~ 18

Author(s):

Mark E. Jones ◽

Ian A. Critchley ◽

James A. Karlowsky ◽

Renée S. Blosser-Middleton ◽

Franz-Josef Schmitz ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Dna Gyrase ◽

Quinolone Resistance ◽

Clinical Isolates ◽

Wild Type ◽

Topoisomerase Iv ◽

Selection Of

ABSTRACT Two 8-methoxy nonfluorinated quinolones (NFQs), PGE 9262932 and PGE 9509924, were tested against contemporary clinical isolates of Staphylococcus aureus (n = 122) and Streptococcus pneumoniae (n = 69) with genetically defined quinolone resistance-determining regions (QRDRs). For S. aureus isolates with wild-type (WT) sequences at the QRDRs, the NFQs demonstrated activities 4- to 32-fold more potent (MICs at which 90% of isolates are inhibited [MIC90s], 0.03 μg/ml) than those of moxifloxacin (MIC90, 0.12 μg/ml), gatifloxacin (MIC90, 0.25 μg/ml), levofloxacin (MIC90, 0.25 μg/ml), and ciprofloxacin (MIC90, 1 μg/ml). Against S. pneumoniae isolates with WT sequences at gyrA and parC, the NFQs PGE 9262932 (MIC90, 0.03 μg/ml) and PGE 9509924 (MIC90, 0.12 μg/ml) were 8- to 64-fold and 2- to 16-fold more potent, respectively, than moxifloxacin (MIC90, 0.25 μg/ml), gatifloxacin (MIC90, 0.5 μg/ml), levofloxacin (MIC90, 2 μg/ml), and ciprofloxacin (MIC90, 2 μg/ml). The MICs of all agents were elevated for S. aureus isolates with alterations in GyrA (Glu88Lys or Ser84Leu) and GrlA (Ser80Phe) and S. pneumoniae isolates with alterations in GyrA (Ser81Phe or Ser81Tyr) and ParC (Ser79Phe or Lys137Asn). Fluoroquinolone MICs for S. aureus strains with double alterations in GyrA combined with double alterations in GrlA were ≥32 μg/ml, whereas the MICs of the NFQs for strains with these double alterations were 4 to 8 μg/ml. The PGE 9262932 and PGE 9509924 MICs for the S. pneumoniae isolates did not exceed 0.5 and 1 μg/ml, respectively, even for isolates with GyrA (Ser81Phe) and ParC (Ser79Phe) alterations, for which levofloxacin MICs were >16 μg/ml. No difference in the frequency of selection of mutations (<10−8 at four times the MIC) in wild-type or first-step mutant isolates of S. aureus or S. pneumoniae was detected for the two NFQs. On the basis of their in vitro activities, these NFQ agents show potential for the treatment of infections caused by isolates resistant to currently available fluoroquinolones.

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1_manuscript_2020-04-14.pdf

10.26434/chemrxiv.12148524.v1 ◽

2020 ◽

Author(s):

Linglan Fang ◽

Jessica Vilas-Boas ◽

sujata chakraborty ◽

zachary potter ◽

Ames Register ◽

...

Keyword(s):

Binding Site ◽

Tyrosine Kinases ◽

Kinase Inhibitors ◽

Catalytic Domain ◽

Major Influence ◽

Atp Binding ◽

Structural Element ◽

Atp Binding Site ◽

Regulatory Architecture

<p>Small molecule kinase inhibitors that stabilize distinct ATP-binding site conformations can differentially modulate the glob-al conformation of Src-family kinases (SFKs). However, it is unclear which specific ATP-binding site contacts are responsible for modulating the global conformation of SFKs and whether these inhibitor-mediated allosteric effects are general to other tyrosine kinases. Here, we describe the development of chemical probes that allow us to deconvolute which features in the ATP-binding site are responsible for the allosteric modulation of the global conformation of Src. We find that the ability of an inhibitor to modulate the global conformation of Src’s regulatory domain-catalytic domain module relies mainly on the influence it has on the conformation of a structural element called helix aC. Furthermore, by developing a set of orthogonal probes that target a drug-sensitized Src variant, we show that stabilizing Src’s helix aC in an active conformation is sufficient to promote a Src-mediated, phosphotransferase-independent alteration in cell morphology. Finally, we report that ATP-competitive, conformation-selective inhibitors can influence the global conformation of tyrosine kinases beyond the SFKs, suggesting that the allosteric networks we observe in Src are conserved in kinases that have a similar regulatory architecture. Taken together, our study highlights that an ATP-competitive inhibitor’s interactions with helix aC can have a major influence on the global conformation of some tyrosine kinases in vitro and in cells.</p>

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How ATP-Competitive Inhibitors Allosterically Modulate Tyrosine Kinases That Contain a Src-like Regulatory Architecture

10.26434/chemrxiv.12148524 ◽

2020 ◽

Author(s):

Linglan Fang ◽

Jessica Vilas-Boas ◽

sujata chakraborty ◽

zachary potter ◽

Ames Register ◽

...

Keyword(s):

Binding Site ◽

Tyrosine Kinases ◽

Kinase Inhibitors ◽

Catalytic Domain ◽

Major Influence ◽

Atp Binding ◽

Structural Element ◽

Atp Binding Site ◽

Regulatory Architecture

<p>Small molecule kinase inhibitors that stabilize distinct ATP-binding site conformations can differentially modulate the glob-al conformation of Src-family kinases (SFKs). However, it is unclear which specific ATP-binding site contacts are responsible for modulating the global conformation of SFKs and whether these inhibitor-mediated allosteric effects are general to other tyrosine kinases. Here, we describe the development of chemical probes that allow us to deconvolute which features in the ATP-binding site are responsible for the allosteric modulation of the global conformation of Src. We find that the ability of an inhibitor to modulate the global conformation of Src’s regulatory domain-catalytic domain module relies mainly on the influence it has on the conformation of a structural element called helix aC. Furthermore, by developing a set of orthogonal probes that target a drug-sensitized Src variant, we show that stabilizing Src’s helix aC in an active conformation is sufficient to promote a Src-mediated, phosphotransferase-independent alteration in cell morphology. Finally, we report that ATP-competitive, conformation-selective inhibitors can influence the global conformation of tyrosine kinases beyond the SFKs, suggesting that the allosteric networks we observe in Src are conserved in kinases that have a similar regulatory architecture. Taken together, our study highlights that an ATP-competitive inhibitor’s interactions with helix aC can have a major influence on the global conformation of some tyrosine kinases in vitro and in cells.</p>

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