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Identification of Staphylococcus aureus Cellular Pathways Affected by the Stilbenoid Lead Drug SK-03-92 Using a Microarray. Antibiotics (Basel) 2017; 6:antibiotics6030017. [PMID: 28892020 PMCID: PMC5617981 DOI: 10.3390/antibiotics6030017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 08/25/2017] [Accepted: 09/07/2017] [Indexed: 12/16/2022] Open
Abstract
The mechanism of action for a new lead stilbene compound coded SK-03-92 with bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) is unknown. To gain insight into the killing process, transcriptional profiling was performed on SK-03-92 treated vs. untreated S. aureus. Fourteen genes were upregulated and 38 genes downregulated by SK-03-92 treatment. Genes involved in sortase A production, protein metabolism, and transcriptional regulation were upregulated, whereas genes encoding transporters, purine synthesis proteins, and a putative two-component system (SACOL2360 (MW2284) and SACOL2361 (MW2285)) were downregulated by SK-03-92 treatment. Quantitative real-time polymerase chain reaction analyses validated upregulation of srtA and tdk as well as downregulation of the MW2284/MW2285 and purine biosynthesis genes in the drug-treated population. A quantitative real-time polymerase chain reaction analysis of MW2284 and MW2285 mutants compared to wild-type cells demonstrated that the srtA gene was upregulated by both putative two-component regulatory gene mutants compared to the wild-type strain. Using a transcription profiling technique, we have identified several cellular pathways regulated by SK-03-92 treatment, including a putative two-component system that may regulate srtA and other genes that could be tied to the SK-03-92 mechanism of action, biofilm formation, and drug persisters.
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Revisiting unexploited antibiotics in search of new antibacterial drug candidates: the case of MSD-819 (6-chloro-2-quinoxalinecarboxylic acid 1,4-dioxide). J Antibiot (Tokyo) 2016; 70:317-319. [DOI: 10.1038/ja.2016.140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/10/2016] [Accepted: 10/23/2016] [Indexed: 11/08/2022]
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Mechanism of action of the novel aminomethylcycline antibiotic omadacycline. Antimicrob Agents Chemother 2013; 58:1279-83. [PMID: 24041885 DOI: 10.1128/aac.01066-13] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Omadacycline is a novel first-in-class aminomethylcycline with potent activity against important skin and pneumonia pathogens, including community-acquired methicillin-resistant Staphylococcus aureus (MRSA), β-hemolytic streptococci, penicillin-resistant Streptococcus pneumoniae, Haemophilus influenzae, and Legionella. In this work, the mechanism of action for omadacycline was further elucidated using a variety of models. Functional assays demonstrated that omadacycline is active against strains expressing the two main forms of tetracycline resistance (efflux and ribosomal protection). Macromolecular synthesis experiments confirmed that the primary effect of omadacycline is on bacterial protein synthesis, inhibiting protein synthesis with a potency greater than that of tetracycline. Biophysical studies with isolated ribosomes confirmed that the binding site for omadacycline is similar to that for tetracycline. In addition, unlike tetracycline, omadacycline is active in vitro in the presence of the ribosomal protection protein Tet(O).
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Ooi N, Chopra I, Eady A, Cove J, Bojar R, O'Neill AJ. Antibacterial activity and mode of action of tert-butylhydroquinone (TBHQ) and its oxidation product, tert-butylbenzoquinone (TBBQ). J Antimicrob Chemother 2013; 68:1297-304. [PMID: 23463211 DOI: 10.1093/jac/dkt030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES The antioxidant tert-butylhydroquinone (TBHQ) is a food additive reported to have antibacterial activity, and may therefore have application in the healthcare setting. This study sought to characterize the antibacterial activity and mode of action of TBHQ and its oxidation product, tert-butylbenzoquinone (TBBQ). METHODS The stability of TBHQ/TBBQ was studied in buffer. Susceptibility testing was performed by broth microdilution, and killing and lytic activity were evaluated by viable counting and culture turbidity measurements. Mode of action studies included following the incorporation of radiolabelled precursors into macromolecules. The effect of TBHQ/TBBQ upon bacterial and mammalian membranes was assessed using the BacLight(TM) assay and by monitoring the haemolysis of equine erythrocytes. RESULTS TBHQ underwent oxidation in solution to form TBBQ. When oxidation was prevented, TBHQ lacked useful antibacterial activity, indicating that TBBQ is responsible for the antibacterial activity attributed to TBHQ. TBBQ demonstrated activity against Staphylococcus aureus SH1000 (MIC 8 mg/L) and against a panel of clinical S. aureus isolates (MIC90 16 mg/L). TBBQ at 4× MIC caused a >4 log10 drop in cell viability within 6 h without lysis, and eradicated staphylococcal biofilms at 8× MIC. TBBQ did not display preferential inhibition of any single macromolecular synthetic pathway, but caused loss of staphylococcal membrane integrity without haemolytic activity. CONCLUSIONS TBBQ is responsible for the antibacterial activity previously ascribed to TBHQ. TBBQ prompts loss of staphylococcal membrane integrity; it is rapidly and extensively bactericidal, but is non-lytic. In view of the potent and selective bactericidal activity of TBBQ, this compound warrants further investigation as a candidate antistaphylococcal agent.
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Affiliation(s)
- N Ooi
- Antimicrobial Research Centre and School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
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Dallmann HG, Fackelmayer OJ, Tomer G, Chen J, Wiktor-Becker A, Ferrara T, Pope C, Oliveira MT, Burgers PMJ, Kaguni LS, McHenry CS. Parallel multiplicative target screening against divergent bacterial replicases: identification of specific inhibitors with broad spectrum potential. Biochemistry 2010; 49:2551-62. [PMID: 20184361 DOI: 10.1021/bi9020764] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Typically, biochemical screens that employ pure macromolecular components focus on single targets or a small number of interacting components. Researches rely on whole cell screens for more complex systems. Bacterial DNA replicases contain multiple subunits that change interactions with each stage of a complex reaction. Thus, the actual number of targets is a multiple of the proteins involved. It is estimated that the overall replication reaction includes up to 100 essential targets, many suitable for discovery of antibacterial inhibitors. We have developed an assay, using purified protein components, in which inhibitors of any of the essential targets can be detected through a common readout. Use of purified components allows each protein to be set within the linear range where the readout is proportional to the extent of inhibition of the target. By performing assays against replicases from model Gram-negative and Gram-positive bacteria in parallel, we show that it is possible to distinguish compounds that inhibit only a single bacterial replicase from those that exhibit broad spectrum potential.
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Affiliation(s)
- H Garry Dallmann
- Department of Chemistry and Biochemistry, University of Colorado, Campus Box 215, Boulder, Colorado 80309, USA
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Role of the (p)ppGpp synthase RSH, a RelA/SpoT homolog, in stringent response and virulence of Staphylococcus aureus. Infect Immun 2010; 78:1873-83. [PMID: 20212088 DOI: 10.1128/iai.01439-09] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In most bacteria, nutrient limitations provoke the stringent control through the rapid synthesis of the alarmones pppGpp and ppGpp. Little is known about the stringent control in the human pathogen Staphylococcus aureus, partly due to the essentiality of the major (p)ppGpp synthase/hydrolase enzyme RSH (RelA/SpoT homolog). Here, we show that mutants defective only in the synthase domain of RSH (rsh(syn)) are not impaired in growth under nutrient-rich conditions. However, these mutants were more sensitive toward mupirocin and were impaired in survival when essential amino acids were depleted from the medium. RSH is the major enzyme responsible for (p)ppGpp synthesis in response to amino acid deprivation (lack of Leu/Val) or mupirocin treatment. Transcriptional analysis showed that the RSH-dependent stringent control in S. aureus is characterized by repression of genes whose products are predicted to be involved in the translation machinery and by upregulation of genes coding for enzymes involved in amino acid metabolism and transport which are controlled by the repressor CodY. Amino acid starvation also provoked stabilization of the RNAs coding for major virulence regulators, such as SaeRS and SarA, independently of RSH. In an animal model, the rsh(syn) mutant was shown to be less virulent than the wild type. Virulence could be restored by the introduction of a codY mutation into the rsh(syn) mutant. These results indicate that stringent conditions are present during infection and that RSH-dependent derepression of CodY-regulated genes is essential for virulence in S. aureus.
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Hobbs JK, Miller K, O'Neill AJ, Chopra I. Consequences of daptomycin-mediated membrane damage in Staphylococcus aureus. J Antimicrob Chemother 2008; 62:1003-8. [PMID: 18669516 DOI: 10.1093/jac/dkn321] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The proposed lethal action of daptomycin on Staphylococcus aureus results from the loss of K(+) and membrane depolarization. However, whether these events alone cause cell death has been questioned. We sought to determine whether other consequences of daptomycin-mediated membrane damage may contribute to cell death. METHODS Previously established assays were used to evaluate the membrane damaging activity of daptomycin at a single time-point of 10 min. More detailed time-course experiments were also performed to determine the kinetics of membrane depolarization and leakage of K(+), Mg(2+) and ATP. The kinetics of inhibition of macromolecular synthesis following exposure to daptomycin were also determined by assaying the incorporation of radioactive precursors into macromolecules. RESULTS Daptomycin exhibited no membrane damaging activity in single time-point assays following exposure to the antibiotic for 10 min. Kinetic analysis confirmed these results as leakage of intracellular components did not occur until 20-30 min, membrane depolarization was gradual and cells remained biosynthetically active for at least 30 min after exposure to daptomycin. Viability declined rapidly after exposure to daptomycin and appeared to precede other detectable changes. CONCLUSIONS These data show that daptomycin-induced loss of Mg(2+) and ATP occurs in conjunction with the previously reported leakage of K(+) and membrane depolarization. We propose that the lethal activity of daptomycin is not simply due to loss of K(+) and probably involves more general damage to the membrane.
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Affiliation(s)
- Joanne Karen Hobbs
- Antimicrobial Research Centre and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
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In vitro efficacy of diclofenac against Listeria monocytogenes. Eur J Clin Microbiol Infect Dis 2008; 27:315-9. [PMID: 18188616 DOI: 10.1007/s10096-007-0439-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Accepted: 11/23/2007] [Indexed: 10/22/2022]
Abstract
Chemotherapy is often futile in systemic listeriosis, translating to being a peril to public health. There is, thus, an imperative need for novel antilisterial compounds, possibly acting through mechanisms dissimilar to those of existing drugs. The present study describes one such agent-the non-steroidal anti-inflammatory drug (NSAID) diclofenac sodium (Dc). The National Committee for Clinical Laboratory Standards (NCCLS) minimum inhibitory concentration (MIC), mode of action, and two mechanisms of action, i.e., on bacterial DNA and membrane, have been characterized with respect to Dc. The drug showed noteworthy inhibitory action (MIC90 = 50 microg/ml) against Listeria strains, demonstrated cidal (minimum bactericidal concentration [MBC]=100 microg/ml) activity, inhibited listerial DNA synthesis (45.48%; incorporation of [methyl-3H] thymidine), and possessed bacterial membrane-damaging activity (37.33%; BacLight assay). Dc could be used as a lead compound for the synthesis of new, more active agents perhaps devoid of side effects. Further, quantitative structure-activity relationship (QSAR) studies will contribute to a new generation of promising adjuvants to existing antilisterial drugs.
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Hurdle JG, O'Neill AJ, Chopra I. Prospects for aminoacyl-tRNA synthetase inhibitors as new antimicrobial agents. Antimicrob Agents Chemother 2005; 49:4821-33. [PMID: 16304142 PMCID: PMC1315952 DOI: 10.1128/aac.49.12.4821-4833.2005] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Julian Gregston Hurdle
- Antimicrobial Research Centre and School of Biochemistry and Microbiology, University of Leeds, Leeds LS2 9JT, United Kingdom
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Beyer D, Kroll HP, Endermann R, Schiffer G, Siegel S, Bauser M, Pohlmann J, Brands M, Ziegelbauer K, Haebich D, Eymann C, Brötz-Oesterhelt H. New class of bacterial phenylalanyl-tRNA synthetase inhibitors with high potency and broad-spectrum activity. Antimicrob Agents Chemother 2004; 48:525-32. [PMID: 14742205 PMCID: PMC321521 DOI: 10.1128/aac.48.2.525-532.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2003] [Revised: 08/24/2003] [Accepted: 10/14/2003] [Indexed: 11/20/2022] Open
Abstract
Phenylalanyl (Phe)-tRNA synthetase (Phe-RS) is an essential enzyme which catalyzes the transfer of phenylalanine to the Phe-specific transfer RNA (tRNA(Phe)), a key step in protein biosynthesis. Phenyl-thiazolylurea-sulfonamides were identified as a novel class of potent inhibitors of bacterial Phe-RS by high-throughput screening and chemical variation of the screening hit. The compounds inhibit Phe-RS of Escherichia coli, Haemophilus influenzae, Streptococcus pneumoniae, and Staphylococcus aureus, with 50% inhibitory concentrations in the nanomolar range. Enzyme kinetic measurements demonstrated that the compounds bind competitively with respect to the natural substrate Phe. All derivatives are highly selective for the bacterial Phe-RS versus the corresponding mammalian cytoplasmic and human mitochondrial enzymes. Phenyl-thiazolylurea-sulfonamides displayed good in vitro activity against Staphylococcus, Streptococcus, Haemophilus, and Moraxella strains, reaching MICs below 1 micro g/ml. The antibacterial activity was partly antagonized by increasing concentrations of Phe in the culture broth in accordance with the competitive binding mode. Further evidence that inhibition of tRNA(Phe) charging is the antibacterial principle of this compound class was obtained by proteome analysis of Bacillus subtilis. Here, the phenyl-thiazolylurea-sulfonamides induced a protein pattern indicative of the stringent response. In addition, an E. coli strain carrying a relA mutation and defective in stringent response was more susceptible than its isogenic relA(+) parent strain. In vivo efficacy was investigated in a murine S. aureus sepsis model and a S. pneumoniae sepsis model in rats. Treatment with the phenyl-thiazolylurea-sulfonamides reduced the bacterial titer in various organs by up to 3 log units, supporting the potential value of Phe-RS as a target in antibacterial therapy.
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Affiliation(s)
- Dieter Beyer
- Department of Anti-Infectives, Pharma Research, Bayer Healthcare AG, D-42096 Wuppertal, Germany
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Oliva B, Miller K, Caggiano N, O'Neill AJ, Cuny GD, Hoemann MZ, Hauske JR, Chopra I. Biological properties of novel antistaphylococcal quinoline-indole agents. Antimicrob Agents Chemother 2003; 47:458-66. [PMID: 12543644 PMCID: PMC151732 DOI: 10.1128/aac.47.2.458-466.2003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antibacterial properties of novel quinoline-indole (QI) agents were examined. QI agents demonstrated potent bactericidal activities against Staphylococcus aureus, killing by lytic and nonlytic mechanisms. S. aureus mutants resistant to a lytic QI agent (SEP 155342) and a nonlytic QI agent (SEP 118843) arose at frequencies of 1.4 x 10(-9) and 1.2 x 10(-8), respectively, by selection at four times the MICs. Mutants resistant to QI agent SEP 155342 were unstable, but mutants resistant to QI agent SEP 118843 displayed stable resistance. Mutants resistant to QI agent SEP 118843 were not cross resistant to other inhibitors, including QI agent SEP 155342. Addition of QI agents SEP 118843 and SEP 155342 at four times the MIC caused nonspecific inhibition of several macromolecular biosynthetic pathways in S. aureus. Within 10 min, QI agents SEP 118843 and SEP 155342 both interfered with bacterial membrane integrity, as measured by uptake of propidium iodide. Agents from the two classes of the QI agents probably kill staphylococci by separate mechanisms which, nevertheless, both involve interference with cytoplasmic membrane function. Precise structure-activity relationships for the division of QI agents into two classes could not be determined. However, lytic activity was often associated with substitution of a basic amine at position 4 of the quinoline nucleus, whereas compounds with nonlytic activity usually contained an aromatic ring with or without a methoxy substituent at position 4. Nonlytic QI agents such as SEP 118843 may possess selective activity against the prokaryotic membrane since this compound failed to lyse mouse erythrocytes when it was added at a concentration equivalent to four times the MIC for S. aureus.
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Affiliation(s)
- Brunello Oliva
- Department of Experimental Medicine, University of L'Aquila, Coppito-67100, L'Aquila, Italy
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Abstract
AIM To determine the bioavailability of mupirocin in human nasal secretions and to assess whether the contents of nasal secretions interact appreciably with this antibiotic. METHODS The comparative bioavailability of mupirocin and chlorhexidine in nasal secretions was determined by bioassay after one, four, and eight hours of incubation with pooled secretions from three subjects. The interaction of mupirocin with nasal secretions was characterised by matrix assisted laser desorption time of flight mass spectrometry (MALDI-TOF). RESULTS MALDI-TOF analysis showed that mupirocin was not absorbed by the main fraction of pooled nasal secretions and should remain active. In bioassay, mupirocin retained 100% of its antistaphylococcal activity in nasal secretions, whereas chlorhexidine was significantly reduced from 100 mg/litre to 1.5 mg/litre and from 1000 mg/litre to 38.5 mg/litre, irrespective of incubation time. CONCLUSIONS The high bioavailability of mupirocin in nasal secretions results from the lack of appreciable molecular interactions.
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Affiliation(s)
- R L R Hill
- South London Public Health Laboratory and Department of Infection, Guy's, King's, and St Thomas's School of Medicine, King's Denmark Hill Campus, Bessemer Road, London SE5 9PJ, UK.
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Oliva B, O'Neill A, Wilson JM, O'Hanlon PJ, Chopra I. Antimicrobial properties and mode of action of the pyrrothine holomycin. Antimicrob Agents Chemother 2001; 45:532-9. [PMID: 11158751 PMCID: PMC90323 DOI: 10.1128/aac.45.2.532-539.2001] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Holomycin, a member of the pyrrothine class of antibiotics, displayed broad-spectrum antibacterial activity, inhibiting a variety of gram-positive and gram-negative bacteria, with the exception of Enterobacter cloacae, Morganella morganii, and Pseudomonas aeruginosa. The antibiotic lacked activity against the eukaryotic microorganisms Saccharomyces cerevisiae and Candida kefyr. Holomycin exhibited a bacteriostatic response against Escherichia coli that was associated with rapid inhibition of RNA synthesis in whole cells. Inhibition of RNA synthesis could have been a secondary consequence of inhibiting tRNA aminoacylation, thereby inducing the stringent response. However, the levels of inhibition of RNA synthesis by holomycin were similar in a stringent and relaxed pair of E. coli strains that were isogenic except for the deletion of the relA gene. This suggests that inhibition of RNA synthesis by holomycin could reflect direct inhibition of DNA-dependent RNA polymerase. Examination of the effects of holomycin on the kinetics of the appearance of beta-galactosidase in induced E. coli cells was also consistent with inhibition of RNA polymerase at the level of RNA chain elongation. However, holomycin only weakly inhibited E. coli RNA polymerase in assays using synthetic poly(dA-dT) and plasmid templates. Furthermore, inhibition of RNA polymerase was observed only at holomycin concentrations in excess of those required to inhibit the growth of E. coli. It is possible that holomycin is a prodrug, requiring conversion in the cell to an active species that inhibits RNA polymerase.
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Affiliation(s)
- B Oliva
- Department of Experimental Medicine, University of L'Aquila, Coppito-67100, L'Aquila, Italy
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Pope AJ, Moore KJ, McVey M, Mensah L, Benson N, Osbourne N, Broom N, Brown MJ, O'Hanlon P. Characterization of isoleucyl-tRNA synthetase from Staphylococcus aureus. II. Mechanism of inhibition by reaction intermediate and pseudomonic acid analogues studied using transient and steady-state kinetics. J Biol Chem 1998; 273:31691-701. [PMID: 9822630 DOI: 10.1074/jbc.273.48.31691] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The interactions of isoleucyl-tRNA synthetase (IleRS, E) from Staphylococcus aureus with both intermediate analogues and pseudomonic acid (PS-A) have been investigated using transient and steady-state techniques. Non-hydrolyzable analogues of isoleucyl-AMP (I) were simple competitive inhibitors (Ile-ol-AMP, Ki = 50 nM and Ile-NHSO2-AMP, Ki = 1 nM;). PS-A (J) inhibits IleRS via a slow-tight binding competitive mechanism where E.J (Kj = approximately 2 nM), undergoes an isomerization to form a stabilized E*.J complex (K*j = 50 pM). To overcome tight-binding artifacts when K*j << [E], K*j values were estimated from PPi/ATP exchange where [S] >> Km, thus raising K*j,app well above [E]. Using [3H]PS-A, it was confirmed that binding occurs with 1:1 stoichiometry and is reversible. Formation of inhibitor complexes was monitored directly through changes in enzyme tryptophan fluorescence. For Ile-ol-AMP and Ile-NHSO2-AMP, the fluorescence intensity of E.I was identical to that when E.Ile-AMP forms catalytically. Binding of PS-A induced only a small change in IleRS fluorescence that was characterized using transient kinetic competition. SB-205952, a PS-A analogue, produced a 37% quenching of IleRS fluorescence upon binding as a result of radiationless energy transfer. Inhibitor reversal rates were obtained by measuring relaxation between spectroscopically different complexes. Together, these data represent a comprehensive solution to the kinetics of inhibition by these compounds.
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Affiliation(s)
- A J Pope
- Department, SmithKline Beecham, New Frontiers Science Park, Harlow, Essex, United Kingdom.
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Chopra I, Hodgson J, Metcalf B, Poste G. The search for antimicrobial agents effective against bacteria resistant to multiple antibiotics. Antimicrob Agents Chemother 1997; 41:497-503. [PMID: 9055982 PMCID: PMC163740 DOI: 10.1128/aac.41.3.497] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- I Chopra
- Department of Microbiology, University of Leeds, United Kingdom.
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