scholarly journals Oxadiazoles Have Butyrate-Specific Conditional Activity against Mycobacterium tuberculosis

2016 ◽  
Vol 60 (6) ◽  
pp. 3608-3616 ◽  
Author(s):  
Julie V. Early ◽  
Allen Casey ◽  
Maria Angeles Martinez-Grau ◽  
Isabel C. Gonzalez Valcarcel ◽  
Michal Vieth ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Mammalian Cells ◽  
Sole Carbon Source ◽  
Specific Activity ◽  
Antitubercular Activity ◽  
Content Type ◽  
Phenotypic Screen

Mycobacterium tuberculosisis a global pathogen of huge importance which can adapt to several host niche environments in which carbon source availability is likely to vary. We developed and ran a phenotypic screen using butyrate as the sole carbon source to be more reflective of the host lung environment. We screened a library of ∼87,000 small compounds and identified compounds which demonstrated good antitubercular activity againstM. tuberculosisgrown with butyrate but not with glucose as the carbon source. Among the hits, we identified an oxadiazole series (six compounds) which had specific activity againstM. tuberculosisbut which lacked cytotoxicity against mammalian cells.

scholarly journals Structure-Based Drug Design and Characterization of Sulfonyl-Piperazine Benzothiazinone Inhibitors of DprE1 from Mycobacterium tuberculosis

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Jérémie Piton ◽  
Anthony Vocat ◽  
Andréanne Lupien ◽  
Caroline S. Foo ◽  
Olga Riabova ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Design ◽  
Antitubercular Activity ◽  
Cysteine Residue ◽  
Drug Candidate ◽  
Structure Based Drug Design ◽  
Content Type ◽  
Active Site Cysteine ◽  
Covalent Adducts

ABSTRACT Macozinone (MCZ) is a tuberculosis (TB) drug candidate that specifically targets the essential flavoenzyme DprE1, thereby blocking synthesis of the cell wall precursor decaprenyl phosphoarabinose (DPA) and provoking lysis of Mycobacterium tuberculosis. As part of the MCZ backup program, we exploited structure-guided drug design to produce a new series of sulfone-containing derivatives, 2-sulfonylpiperazin 8-nitro 6-trifluoromethyl 1,3-benzothiazin-4-one, or sPBTZ. These compounds are less active than MCZ but have a better solubility profile, and some derivatives display enhanced stability in microsomal assays. DprE1 was efficiently inhibited by sPBTZ, and covalent adducts with the active-site cysteine residue (C387) were formed. However, despite the H-bonding potential of the sulfone group, no additional bonds were seen in the crystal structure of the sPBTZ-DprE1 complex with compound 11326127 compared to MCZ. Compound 11626091, the most advanced sPBTZ, displayed good antitubercular activity in the murine model of chronic TB but was less effective than MCZ. Nonetheless, further testing of this MCZ backup compound is warranted as part of combination treatment with other TB drugs.

scholarly journals Mycobacterium tuberculosis Is Able To Accumulate and Utilize Cholesterol

2009 ◽  
Vol 191 (21) ◽  
pp. 6584-6591 ◽  
Author(s):  
Anna Brzostek ◽  
Jakub Pawelczyk ◽  
Anna Rumijowska-Galewicz ◽  
Bozena Dziadek ◽  
Jaroslaw Dziadek
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Cytoplasmic Membrane ◽  
Degradation Pathway ◽  
Cholesterol Accumulation ◽  
Targeted Disruption ◽  
Future Studies

ABSTRACT It is expected that the obligatory human pathogen Mycobacterium tuberculosis must adapt metabolically to the various nutrients available during its cycle of infection, persistence, and reactivation. Cholesterol, which is an important part of the mammalian cytoplasmic membrane, is a potential energy source. Here, we show that M. tuberculosis grown in medium containing a carbon source other than cholesterol is able to accumulate cholesterol in the free-lipid zone of its cell wall. This cholesterol accumulation decreases the permeability of the cell wall for the primary antituberculosis drug, rifampin, and partially masks the mycobacterial surface antigens. Furthermore, M. tuberculosis was able to grow on mineral medium supplemented with cholesterol as the sole carbon source. Targeted disruption of the Rv3537 (kstD) gene inhibited growth due to inactivation of the cholesterol degradation pathway, as evidenced by accumulation of the intermediate, 9-hydroxy-4-androstene-3,17-dione. Our findings that M. tuberculosis is able to accumulate cholesterol in the presence of alternative nutrients and use it when cholesterol is the sole carbon source in vitro may facilitate future studies into the pathophysiology of this important deadly pathogen.

scholarly journals Engineered Pentafunctional Minicellulosome for Simultaneous Saccharification and Ethanol Fermentation in Saccharomyces cerevisiae

2014 ◽  
Vol 80 (21) ◽  
pp. 6677-6684 ◽  
Author(s):  
Youyun Liang ◽  
Tong Si ◽  
Ee Lui Ang ◽  
Huimin Zhao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Phosphoric Acid ◽  
Sole Carbon Source ◽  
Consolidated Bioprocessing ◽  
Content Type ◽  
Yeast Strains ◽  
Recombinant Yeast Strain ◽  
Polysaccharide Monooxygenases ◽  
Simultaneous Saccharification

ABSTRACTSeveral yeast strains have been engineered to express different cellulases to achieve simultaneous saccharification and fermentation of lignocellulosic materials. However, successes in these endeavors were modest, as demonstrated by the relatively low ethanol titers and the limited ability of the engineered yeast strains to grow using cellulosic materials as the sole carbon source. Recently, substantial enhancements to the breakdown of cellulosic substrates have been observed when lytic polysaccharide monooxygenases (LPMOs) were added to traditional cellulase cocktails. LPMOs are reported to cleave cellulose oxidatively in the presence of enzymatic electron donors such as cellobiose dehydrogenases. In this study, we coexpressed LPMOs and cellobiose dehydrogenases with cellobiohydrolases, endoglucanases, and β-glucosidases inSaccharomyces cerevisiae. These enzymes were secreted and docked onto surface-displayed miniscaffoldins through cohesin-dockerin interaction to generate pentafunctional minicellulosomes. The enzymes on the miniscaffoldins acted synergistically to boost the degradation of phosphoric acid swollen cellulose and increased the ethanol titers from our previously achieved levels of 1.8 to 2.7 g/liter. In addition, the newly developed recombinant yeast strain was also able to grow using phosphoric acid swollen cellulose as the sole carbon source. The results demonstrate the promise of the pentafunctional minicellulosomes for consolidated bioprocessing by yeast.

scholarly journals Biodegradation of Polyester Polyurethane by Endophytic Fungi

2011 ◽  
Vol 77 (17) ◽  
pp. 6076-6084 ◽  
Author(s):  
Jonathan R. Russell ◽  
Jeffrey Huang ◽  
Pria Anand ◽  
Kaury Kucera ◽  
Amanda G. Sandoval ◽  
...  
Keyword(s):  
Carbon Source ◽  
Endophytic Fungi ◽  
Sole Carbon Source ◽  
Anaerobic Growth ◽  
Serine Hydrolase ◽  
Microbial World ◽  
Content Type ◽  
Metabolic Properties ◽  
Liquid Suspensions ◽  
Promising Source

ABSTRACTBioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genusPestalotiopsis, although it was not a universal feature of this genus. TwoPestalotiopsis microsporaisolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation.

scholarly journals Novel Antimicrobials from Uncultured Bacteria Acting against Mycobacterium tuberculosis

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Jeffrey Quigley ◽  
Aaron Peoples ◽  
Asel Sarybaeva ◽  
Dallas Hughes ◽  
Meghan Ghiglieri ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Natural Product ◽  
Protein Secretion ◽  
Specific Activity ◽  
Therapeutic Options ◽  
Content Type ◽  
Natural Product Discovery ◽  
Uncultured Bacteria ◽  
New Compounds ◽  
Drug Resistant Strains

ABSTRACT Mycobacterium tuberculosis, which causes tuberculosis (TB), is estimated to infect one-third of the world’s population. The overall burden and the emergence of drug-resistant strains of Mycobacterium tuberculosis underscore the need for new therapeutic options against this important human pathogen. Our recent work demonstrated the success of natural product discovery in identifying novel compounds with efficacy against Mycobacterium tuberculosis. Here, we improve on these methods by combining improved isolation and Mycobacterium tuberculosis selective screening to identify three new anti-TB compounds: streptomycobactin, kitamycobactin, and amycobactin. We were unable to obtain mutants resistant to streptomycobactin, and its target remains to be elucidated. We identify the target of kitamycobactin to be the mycobacterial ClpP1P2C1 protease and confirm that kitamycobactin is an analog of the previously identified compound lassomycin. Further, we identify the target of amycobactin to be the essential protein secretion pore SecY. We show further that amycobactin inhibits protein secretion via the SecY translocon. Importantly, this inhibition is bactericidal to nonreplicating Mycobacterium tuberculosis. This is the first compound, to our knowledge, that targets the Sec protein secretion machinery in Mycobacterium tuberculosis. This work underscores the ability of natural product discovery to deliver not only new compounds with activity against Mycobacterium tuberculosis but also compounds with novel targets. IMPORTANCE Decreasing discovery rates and increasing resistance have underscored the need for novel therapeutic options to treat Mycobacterium tuberculosis infection. Here, we screen extracts from previously uncultured soil microbes for specific activity against Mycobacterium tuberculosis, identifying three novel compounds. We further define the mechanism of action of one compound, amycobactin, and demonstrate that it inhibits protein secretion through the Sec translocation machinery.

scholarly journals Genome Sequence of Bacillus megaterium O1, a Saponin-Degrading Bacterium

2020 ◽  
Vol 9 (40) ◽  
Author(s):  
Cassandra E. Overney ◽  
Jean J. Huang
Keyword(s):  
Carbon Source ◽  
Genome Sequence ◽  
Bacillus Megaterium ◽  
Sole Carbon Source ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Content Type ◽  
Degrading Bacterium ◽  
Sapindus Saponaria ◽  
Insight Into

ABSTRACT Bacillus megaterium strain O1 was isolated from a soapnut (Sapindus saponaria) surface and degrades Quillaja saponin as a sole carbon source. We report the draft genome sequence of B. megaterium O1, which has an estimated size of 5.1 Mb. Study of this isolate will provide insight into mechanisms of saponin degradation.

scholarly journals Structure-Activity Relationships of Wollamide Cyclic Hexapeptides with Activity against Drug-Resistant and Intracellular Mycobacterium tuberculosis

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Zeinab G. Khalil ◽  
Timothy A. Hill ◽  
Luis M. De Leon Rodriguez ◽  
Rink-Jan Lohman ◽  
Huy N. Hoang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mammalian Cells ◽  
Antimycobacterial Activity ◽  
Drug Resistant ◽  
Amino Acid Residues ◽  
Content Type ◽  
Cyclic Hexapeptides ◽  
Rats And Mice

ABSTRACT Wollamides are cyclic hexapeptides, recently isolated from an Australian soil Streptomyces isolate, that exhibit promising in vitro antimycobacterial activity against Mycobacterium bovis Bacille Calmette Guérin without displaying cytotoxicity against a panel of mammalian cells. Here, we report the synthesis and antimycobacterial activity of 36 new synthetic wollamides, collated with all known synthetic and natural wollamides, to reveal structure characteristics responsible for in vitro growth-inhibitory activity against Mycobacterium tuberculosis (H37Rv, H37Ra, CDC1551, HN878, and HN353). The most potent antimycobacterial wollamides were those where residue VI d-Orn (wollamide B) was replaced by d-Arg (wollamide B1) or d-Lys (wollamide B2), with all activity being lost when residue VI was replaced by Gly, l-Arg, or l-Lys (wollamide B3). Substitution of other amino acid residues mainly reduced or ablated antimycobacterial activity. Significantly, whereas wollamide B2 was the most potent in restricting M. tuberculosis in vitro, wollamide B1 restricted M. tuberculosis intracellular burden in infected macrophages. Wollamide B1 synergized with pretomanid (PA-824) in inhibiting M. tuberculosis in vitro growth but did not antagonize prominent first- and second-line tuberculosis antibiotics. Furthermore, wollamide B1 exerted bactericidal activity against nonreplicating M. tuberculosis and impaired growth of multidrug- and extensively drug-resistant clinical isolates. In vivo pharmacokinetic profiles for wollamide B1 in rats and mice encourage further optimization of the wollamide pharmacophore for in vivo bioavailability. Collectively, these observations highlight the potential of the wollamide antimycobacterial pharmacophore.

scholarly journals Triosephosphate Isomerase Is Dispensable In Vitro yet Essential for Mycobacterium tuberculosis To Establish Infection

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Carolina Trujillo ◽  
Antje Blumenthal ◽  
Joeli Marrero ◽  
Kyu Y. Rhee ◽  
Dirk Schnappinger ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Carbon Source ◽  
Triosephosphate Isomerase ◽  
Central Carbon Metabolism ◽  
Dihydroxyacetone Phosphate ◽  
Content Type ◽  
Carbon Substrates ◽  
Metabolic Conditions ◽  
Single Carbon Source

ABSTRACTTriosephosphate isomerase (TPI) catalyzes the interconversion of dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). This reaction is required for glycolysis and gluconeogenesis, andtpihas been predicted to be essential for growth ofMycobacterium tuberculosis. However, when studying a conditionally regulatedtpiknockdown mutant, we noticed that depletion of TPI reduced growth ofM. tuberculosisin media containing a single carbon source but not in media that contained both a glycolytic and a gluconeogenic carbon source. We used such two-carbon-source media to isolate atpideletion (Δtpi) mutant. The Δtpimutant did not survive with single carbon substrates but grew like wild-type (WT)M. tuberculosisin the presence of both a glycolytic and a gluconeogenic carbon source.13C metabolite tracing revealed the accumulation of TPI substrates in Δtpiand the absence of alternative triosephosphate isomerases and metabolic bypass reactions, which confirmed the requirement of TPI for glycolysis and gluconeogenesis inM. tuberculosis. The Δtpistrain was furthermore severely attenuated in the mouse model of tuberculosis, suggesting thatM. tuberculosiscannot simultaneously access sufficient quantities of glycolytic and gluconeogenic carbon substrates to establish infection in mice.IMPORTANCEThe importance of central carbon metabolism for the pathogenesis ofM. tuberculosishas recently been recognized, but the consequences of depleting specific metabolic enzymes remain to be identified for many enzymes. We investigated triosephosphate isomerase (TPI) because it is central to both glycolysis and gluconeogenesis and had been predicted to be essential for growth ofM. tuberculosis. This work identified metabolic conditions that make TPI dispensable forM. tuberculosisgrowth in culture and proved thatM. tuberculosisrelies on a single TPI enzyme and has no metabolic bypass for the TPI-dependent interconversion of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate in glycolysis and gluconeogenesis. Finally, we demonstrate that TPI is essential for growth of the pathogen in mouse lungs.

scholarly journals Pantothenate and Pantetheine Antagonize the Antitubercular Activity of Pyrazinamide

2014 ◽  
Vol 58 (12) ◽  
pp. 7258-7263 ◽  
Author(s):  
Nicholas A. Dillon ◽  
Nicholas D. Peterson ◽  
Brandon C. Rosen ◽  
Anthony D. Baughn
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nicotinic Acid ◽  
Active Form ◽  
Laboratory Strain ◽  
Antitubercular Activity ◽  
First Line ◽  
Auxotrophic Strain ◽  
Content Type ◽  
Related Compounds ◽  
Pyrazinoic Acid

ABSTRACTPyrazinamide (PZA) is a first-line tuberculosis drug that inhibits the growth ofMycobacterium tuberculosisvia an as yet undefined mechanism. AnM. tuberculosislaboratory strain that was auxotrophic for pantothenate was found to be insensitive to PZA and to the active form, pyrazinoic acid (POA). To determine whether this phenotype was strain or condition specific, the effect of pantothenate supplementation on PZA activity was assessed using prototrophic strains ofM. tuberculosis. It was found that pantothenate and other β-alanine-containing metabolites abolished PZA and POA susceptibility, suggesting that POA might selectively target pantothenate synthesis. However, when the pantothenate-auxotrophic strain was cultivated using a subantagonistic concentration of pantetheine in lieu of pantothenate, susceptibility to PZA and POA was restored. In addition, we found that β-alanine could not antagonize PZA and POA activity against the pantothenate-auxotrophic strain, indicating that the antagonism is specific to pantothenate. Moreover, pantothenate-mediated antagonism was observed for structurally related compounds, includingn-propyl pyrazinoate, 5-chloropyrazinamide, and nicotinamide, but not for nicotinic acid or isoniazid. Taken together, these data demonstrate that while pantothenate can interfere with the action of PZA, pantothenate synthesis is not directly targeted by PZA. Our findings suggest that targeting of pantothenate synthesis has the potential to enhance PZA efficacy and possibly to restore PZA susceptibility in isolates withpanD-linked resistance.

scholarly journals Genetically Modified Strains of Ralstonia eutropha H16 with β-Ketothiolase Gene Deletions for Production of Copolyesters with Defined 3-Hydroxyvaleric Acid Contents

2012 ◽  
Vol 78 (15) ◽  
pp. 5375-5383 ◽  
Author(s):  
Nicole Lindenkamp ◽  
Elena Volodina ◽  
Alexander Steinbüchel
Keyword(s):  
Fatty Acids ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Ralstonia Eutropha ◽  
Carbon Sources ◽  
Production Capacity ◽  
Wild Type ◽  
Content Type ◽  
Storage Behavior ◽  
Copolymer Poly

ABSTRACTβ-Ketothiolases catalyze the first step of poly(3-hydroxybutyrate) [poly(3HB)] biosynthesis in bacteria by condensation of two acetyl coenzyme A (acetyl-CoA) molecules to acetoacetyl-CoA and also take part in the degradation of fatty acids. During growth on propionate or valerate,Ralstonia eutrophaH16 produces the copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)]. InR. eutropha, 15 β-ketothiolase homologues exist. The synthesis of 3-hydroxybutyryl-CoA (3HB-CoA) could be significantly reduced in an 8-fold mutant (Lindenkamp et al., Appl. Environ. Microbiol. 76:5373–5382, 2010). In this study, a 9-fold mutant deficient in nine β-ketothiolase gene homologues (phaA,bktB, H16_A1713, H16_B1771, H16_A1528, H16_B0381, H16_B1369, H16_A0170, andpcaF) was generated. In order to examine the polyhydroxyalkanoate production capacity when short- or long-chain and even- or odd-chain-length fatty acids were provided as carbon sources, the growth and storage behavior of several mutants from the previous study and the newly generated 9-fold mutant were analyzed. Propionate, valerate, octanoate, undecanoic acid, or oleate was chosen as the sole carbon source. On octanoate, no significant differences in growth or storage behavior were observed between wild-typeR. eutrophaand the mutants. In contrast, during the growth on oleate of a multiple mutant lackingphaA,bktB, and H16_A0170, diminished poly(3HB) accumulation occurred. Surprisingly, the amount of accumulated poly(3HB) in the multiple mutants grown on gluconate differed; it was much lower than that on oleate. The β-ketothiolase activity toward acetoacetyl-CoA in H16ΔphaAand all the multiple mutants remained 10-fold lower than the activity of the wild type, regardless of which carbon source, oleate or gluconate, was employed. During growth on valerate as a sole carbon source, the 9-fold mutant accumulated almost a poly(3-hydroxyvalerate) [poly(3HV)] homopolyester with 99 mol% 3HV constituents.

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