scholarly journals Synthesis and Biological Evaluation of Lipophilic Nucleoside Analogues as Inhibitors of Aminoacyl-tRNA Synthetases

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 180
Author(s):  
Manesh Nautiyal ◽  
Bharat Gadakh ◽  
Steff De Graef ◽  
Luping Pang ◽  
Masroor Khan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Metabolic Activation ◽  
Selective Inhibition ◽  
Biological Evaluation ◽  
Trna Synthetase ◽  
Bacterial Membranes ◽  
Trna Synthetases ◽  
Adenine Ring ◽  
Alkyl Moiety

Emerging antibiotic resistance in pathogenic bacteria and reduction of compounds in the existing antibiotics discovery pipeline is the most critical concern for healthcare professionals. A potential solution aims to explore new or existing targets/compounds. Inhibition of bacterial aminoacyl-tRNA synthetase (aaRSs) could be one such target for the development of antibiotics. The aaRSs are a group of enzymes that catalyze the transfer of an amino acid to their cognate tRNA and therefore play a pivotal role in translation. Thus, selective inhibition of these enzymes could be detrimental to microbes. The 5′-O-(N-(L-aminoacyl)) sulfamoyladenosines (aaSAs) are potent inhibitors of the respective aaRSs, however due to their polarity and charged nature they cannot cross the bacterial membranes. In this work, we increased the lipophilicity of these existing aaSAs in an effort to promote their penetration through the bacterial membrane. Two strategies were followed, either attaching a (permanent) alkyl moiety at the adenine ring via alkylation of the N6-position or introducing a lipophilic biodegradable prodrug moiety at the alpha-terminal amine, totaling eight new aaSA analogues. All synthesized compounds were evaluated in vitro using either a purified Escherichia coli aaRS enzyme or in presence of total cellular extract obtained from E. coli. The prodrugs showed comparable inhibitory activity to the parent aaSA analogues, indicating metabolic activation in cellular extracts, but had little effect on bacteria. During evaluation of the N6-alkylated compounds against different microbes, the N6-octyl containing congener 6b showed minimum inhibitory concentration (MIC) of 12.5 µM against Sarcina lutea while the dodecyl analogue 6c displayed MIC of 6.25 µM against Candida albicans.

scholarly journals Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

scholarly journals Non-Lytic Antibacterial Peptides That Translocate Through Bacterial Membranes to Act on Intracellular Targets

2019 ◽  
Vol 20 (19) ◽  
pp. 4877 ◽  
Author(s):  
Marlon H. Cardoso ◽  
Beatriz T. Meneguetti ◽  
Bruna O. Costa ◽  
Danieli F. Buccini ◽  
Karen G. N. Oshiro ◽  
...  
Keyword(s):  
Cell Wall ◽  
Protein Synthesis ◽  
Pathogenic Bacteria ◽  
Biological Properties ◽  
Antibacterial Peptides ◽  
Bacterial Cells ◽  
Bacterial Membranes ◽  
Intracellular Targets

The advent of multidrug resistance among pathogenic bacteria has attracted great attention worldwide. As a response to this growing challenge, diverse studies have focused on the development of novel anti-infective therapies, including antimicrobial peptides (AMPs). The biological properties of this class of antimicrobials have been thoroughly investigated, and membranolytic activities are the most reported mechanisms by which AMPs kill bacteria. Nevertheless, an increasing number of works have pointed to a different direction, in which AMPs are seen to be capable of displaying non-lytic modes of action by internalizing bacterial cells. In this context, this review focused on the description of the in vitro and in vivo antibacterial and antibiofilm activities of non-lytic AMPs, including indolicidin, buforin II PR-39, bactenecins, apidaecin, and drosocin, also shedding light on how AMPs interact with and further translocate through bacterial membranes to act on intracellular targets, including DNA, RNA, cell wall and protein synthesis.

scholarly journals Lysine Acetylation Regulates Alanyl-tRNA Synthetase Activity in Escherichia coli

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 473 ◽  
Author(s):  
Takuya Umehara ◽  
Saori Kosono ◽  
Dieter Söll ◽  
Koji Tamura
Keyword(s):  
Escherichia Coli ◽  
Trna Synthetase ◽  
Synthetase Activity ◽  
Lysine Acetylation ◽  
Trna Synthetases ◽  
E Coli ◽  
Domains Of Life ◽  
The Impact

Protein lysine acetylation is a widely conserved posttranslational modification in all three domains of life. Lysine acetylation frequently occurs in aminoacyl-tRNA synthetases (aaRSs) from many organisms. In this study, we determined the impact of the naturally occurring acetylation at lysine-73 (K73) in Escherichia coli class II alanyl-tRNA synthetase (AlaRS) on its alanylation activity. We prepared an AlaRS K73Ac variant in which Nε-acetyl-l-lysine was incorporated at position 73 using an expanded genetic code system in E. coli. The AlaRS K73Ac variant showed low activity compared to the AlaRS wild type (WT). Nicotinamide treatment or CobB-deletion in an E. coli led to elevated acetylation levels of AlaRS K73Ac and strongly reduced alanylation activities. We assumed that alanylation by AlaRS is affected by K73 acetylation, and the modification is sensitive to CobB deacetylase in vivo. We also showed that E. coli expresses two CobB isoforms (CobB-L and CobB-S) in vivo. CobB-S displayed the deacetylase activity of the AlaRS K73Ac variant in vitro. Our results imply a potential regulatory role for lysine acetylation in controlling the activity of aaRSs and protein synthesis.

Utp22p acts in concert with Utp8p to channel aminoacyl-tRNA from the nucleolus to the nuclear tRNA export receptor Los1p but not Msn5p

2012 ◽  
Vol 90 (6) ◽  
pp. 731-749 ◽  
Author(s):  
Manoja B.K. Eswara ◽  
Ashley Clayton ◽  
Dev Mangroo
Keyword(s):  
Protein Complex ◽  
Trna Synthetase ◽  
Nuclear Pore ◽  
Independent Manner ◽  
Nuclear Retention ◽  
Trna Synthetases ◽  
U3 Snorna ◽  
Aminoacyl Trna Synthetases ◽  
Export Receptors

Utp8p is an essential nucleolar protein that channels aminoacyl-tRNAs from aminoacyl-tRNA synthetases in the nucleolus to the nuclear tRNA export receptors located in the nucleoplasm and nuclear pore complex in Saccharomyces cerevisiae . Utp8p is also part of the U3 snoRNA-associated protein complex involved in 18S rRNA biogenesis in the nucleolus. We report that Utp22p, which is another member of the U3 snoRNA-associated protein complex, is also an intranuclear component of the nuclear tRNA export machinery. Depletion of Utp22p results in nuclear retention of mature tRNAs derived from intron-containing and intronless precursors. Moreover, Utp22p copurifies with the nuclear tRNA export receptor Los1p, the aminoacyl-tRNA synthetase Tys1p and Utp8p, but not with the RanGTPase Gsp1p and the nuclear tRNA export receptor Msn5p. Utp22p interacts directly with Utp8p and Los1p in a tRNA-independent manner in vitro. Utp22p also interacts directly with Tys1p, but this binding is stimulated when Tys1p is bound to tRNA. However, Utp22p, unlike Utp8p, does not bind tRNA saturably. These data suggest that Utp22p recruits Utp8p to aminoacyl-tRNA synthetases in the nucleolus to collect aminoacyl-tRNA and then accompanies the Utp8p–tRNA complex to deliver the aminoacyl-tRNAs to Los1p but not Msn5p. It is possible that Nrap/Nol6, the mammalian orthologue of Utp22p, plays a role in channelling aminoacyl-tRNA to the nuclear tRNA export receptor exportin-t.

scholarly journals In Silico Toxicological, Anti-Tubercular Effect Evaluation And In Vitro Marine Pathogenic Bacteria Inhibition of N-[(3-Chloro-4-Nitro-Phenyl)Methyleneamino]Pyridine-4-Carboxamidine

2019 ◽  
Vol 9 (6) ◽  
pp. 23-27
Author(s):  
Kamel Mokhnache ◽  
EL-Khamsa Soltani ◽  
Soraya Madoui ◽  
Hanane Khither ◽  
Ahlem Karbab ◽  
...  
Keyword(s):  
In Silico ◽  
Pathogenic Bacteria ◽  
Vibrio Anguillarum ◽  
Subcutaneous Administration ◽  
Covalent Bond ◽  
Metabolic Activation ◽  
Bactericidal Effect ◽  
Effect Evaluation ◽  
Photobacterium Damselae

The hydrazone; N-[(3-chloro-4-nitro-phenyl) methyleneamino] pyridine-4-carboxamidine (H) was selected for in silico toxicological and in vitro bactericidal studies. Toxicological investigation was carried out using software program, such as eMolTox and Gusar, for the toxic substructure determination, and acute rat toxicity prediction respectively. In vitro bactericidal effect evaluation was investigated using tow marine pathogenic bacteria; Vibrio anguillarum and Photobacterium damselae. Computational results determinate toxicophores of (H), which are nitro-aromatic part, hydrazine group, and quaternary carbon, were predicted as responsible for Idiosyncratic toxicity metabolic activation, covalent bond with DNA, and hepatotoxicity respectively. In addition, the predicted LD50 of (H) are 1086, 244, 1816, and 823.40 mg/kg in intraperitenial, intravenous, oral and subcutaneous administration respectively. For bactericidal results, H exhibited an excellent effect with inhibition percentages of 98.65 and 98.83% at the concentrations of 1000 and 500 µg/mL against Vibrio anguillarum respectively, the same effect was demonstrated against Photobacterium damselae with inhibition percentages of 97.74 and 97.98 % at the same concentrations. For anti-tubercular effect prediction, results revealed that H has an excellent effect with probability percentage of 84.6%.   Keyword: Hydrazone, toxicophore, LD50, Anti-tubercular, Vibrio anguillarum, Photobacterium damselae.     

scholarly journals Efficacy of epetraborole against Mycobacterium abscessus is increased with norvaline

2021 ◽  
Author(s):  
Jaryd R Sullivan ◽  
Andreanne Lupien ◽  
Elias Kalthoff ◽  
Claire Hamela ◽  
Lorne Taylor ◽  
...  
Keyword(s):  
Trna Synthetase ◽  
Mycobacterium Abscessus ◽  
Trna Synthetases ◽  
Equilibrium Binding ◽  
Binding Data ◽  
Clp Proteases ◽  
Vitro Data ◽  
In Vitro Data

Certain aminoacyl-tRNA synthetases developed a proofreading mechanism to ensure aminoacylation of tRNAs with cognate amino acids. Epetraborole (EPT) was identified as an inhibitor of the leucyl-tRNA synthetase (LeuRS) editing site in Mycobacterium abscessus. EPT displayed enhanced activity against M. abscessus over Mycobacterium tuberculosis. Crystallographic and equilibrium binding data showed that EPT binds LeuRSMabs and LeuRSMtb with similar Kd. Proteomic analysis revealed that when M. abscessus LeuRS mutants were fed the non-proteinogenic amino acid norvaline, leucine residues in proteins were replaced by norvaline, inducing expression of GroEL chaperonins and Clp proteases. In vitro data revealed that supplementation of media with norvaline reduced the emergence of EPT mutants in both M. abscessus and M. tuberculosis. The combination of EPT and norvaline had improved in vivo efficacy compared to EPT in a murine model of M. abscessus infection.

scholarly journals Biological evaluation of some octanoyl derivatives of methyl 4,6-O-cyclohexylidene-α-D-glucopyranoside

2013 ◽  
pp. 53-64 ◽  
Author(s):  
Abul KMS Kabir ◽  
Sarkar MA Kawsar ◽  
Mohammad MR Bhuiyan ◽  
Md Safiqur Rahman ◽  
Bilkiss Banu
Keyword(s):  
Pathogenic Bacteria ◽  
Biological Evaluation ◽  
Phytopathogenic Fungi ◽  
Bacterial Strains ◽  
Antibacterial And Antifungal Activities ◽  
Inhibition Concentration ◽  
Fungal Phytopathogens ◽  
Antibacterial And Antifungal ◽  
Derivatives Of

Some acylated derivatives of methyl 4,6-O-cyclohexylidene-?-D-glucopyranoside, including the precursor, were employed as test compounds for in vitro antimicrobial functionality test against ten human pathogenic bacteria and six phytopathogenic fungi. For comparative studies, biological activity of standard antibiotics, Ampicillin and Nystatin were also carried out against these microorganisms. The study revealed that the tested samples exhibited moderate to good antibacterial and antifungal activities. It was also observed that the test substances were more effective against fungal phytopathogens than those of the bacterial strains. Encouragingly, a good number of test compounds exhibited better antimicrobial activity than the standard antibiotics employed. Minimum Inhibition Concentration (MIC) test of methyl 4,6-O-cyclohexylidene-3-Odecanoyl- 2-O-octanoyl-?-D-glucopyranoside was conducted against INABA ET (Vibrio) and MIC was found to be 12.5 ?g/disc. DOI: http://dx.doi.org/10.3329/cujbs.v3i1.13406 The Chittagong Univ. J. B. Sci.,Vol. 3(1&2):53-64, 2008

scholarly journals Inhibition of isoleucyl-transfer ribonucleic acid synthetase in Echerichia coli by pseudomonic acid

1978 ◽  
Vol 176 (1) ◽  
pp. 305-318 ◽  
Author(s):  
Julia Hughes ◽  
Graham Mellows
Keyword(s):  
Rna Synthesis ◽  
Inhibitory Effect ◽  
Trna Synthetase ◽  
Threonine Deaminase ◽  
Trna Synthetases ◽  
E Coli ◽  
Naturally Occurring ◽  
Pseudomonic Acid

The mode of action of the antibiotic pseudomonic acid has been studied in Escherichia coli. Pseudomonic acid strongly inhibits protein and RNA synthesis in vivo. The antibiotic had no effect on highly purified DNA-dependent RNA polymerase and showed only a weak inhibitory effect on a poly(U)-directed polyphenylalanine-forming ribosomal preparation. Chloramphenicol reversed inhibition of RNA synthesis in vivo. Pseudomonic acid had little effect on RNA synthesis in a regulatory mutant, E. coli B AS19 RCrel, whereas protein synthesis was strongly inhibited. In pseudomonic acid-treated cells, increased concentrations of ppGpp, pppGpp and ATP were observed, but the GTP pool size decreased, suggesting that inhibition of RNA synthesis is a consequence of the stringent control mechanism imposed by pseudomonic acid-induced deprivation of an amino acid. Of the 20 common amino acids, only isoleucine reversed the inhibitory effect in vivo. The antibiotic was found to be a powerful inhibitor of isoleucyl-tRNA synthetase both in vivo and in vitro. Of seven other tRNA synthetases assayed, only a weak inhibitory effect on phenylalanyl-tRNA synthetase was observed; this presumably accounted for the weak effect on polyphenylalanine formation in a ribosomal preparation. Pseudomonic acid also significantly de-repressed threonine deaminase and transaminase B activity, but not dihydroxyacid dehydratase (isoleucine-biosynthetic enzymes) by decreasing the supply of aminoacylated tRNAIle. Pseudomonic acid is the second naturally occurring inhibitor of bacterial isoleucyl-tRNA synthetase to be discovered, furanomycin being the first.

scholarly journals Characterization of Two Seryl-tRNA Synthetases in Albomycin-Producing Streptomyces sp. Strain ATCC 700974

2009 ◽  
Vol 53 (11) ◽  
pp. 4619-4627 ◽  
Author(s):  
Yu Zeng ◽  
Hervé Roy ◽  
Preeti B. Patil ◽  
Michael Ibba ◽  
Shawn Chen
Keyword(s):  
Genetic Locus ◽  
Biosynthetic Gene Cluster ◽  
Trna Synthetase ◽  
Temperature Sensitive ◽  
Strain Atcc ◽  
Amino Acid Residues ◽  
Trna Synthetases ◽  
Novel Approach ◽  
Signature Sequences

ABSTRACTThe Trojan horse antibiotic albomycin, produced byStreptomycessp. strain ATCC 700974, contains a thioribosyl nucleoside moiety linked to a hydroxamate siderophore through a serine residue. The seryl nucleoside structure (SB-217452) is a potent inhibitor of seryl-tRNA synthetase (SerRS) in the pathogenic bacteriumStaphylococcus aureus, with a 50% inhibitory concentration (IC50) of ∼8 nM. In the albomycin-producingStreptomycessp., a bacterial SerRS homolog (Alb10) was found to be encoded in a biosynthetic gene cluster in addition to anotherserRSgene (serS1) at a different genetic locus. Alb10, named SerRS2 herein, is significantly divergent from SerRS1, which shows high homology to the housekeeping SerRS found in otherStreptomycesspecies. We genetically and biochemically characterized the two genes and the proteins encoded. Both genes were able to complement a temperature-sensitiveserSmutant ofEscherichia coliand allowed growth at a nonpermissive temperature.serS2was shown to confer albomycin resistance, with specific amino acid residues in the motif 2 signature sequences of SerRS2 playing key roles. SerRS1 and SerRS2 are comparably efficient in vitro, but theKmof serine for SerRS2 measured during tRNA aminoacylation is more than 20-fold higher than that for SerRS1. SB-217452 was also enzymatically generated and purified by two-step chromatography. Its IC50against SerRS1 was estimated to be 10-fold lower than that against SerRS2. In contrast, both SerRSs displayed comparable inhibition kinetics for serine hydroxamate, indicating that SerRS2 was specifically resistant to SB-217452. These data suggest that miningStreptomycesgenomes for duplicated aminoacyl-tRNA synthetase genes could provide a novel approach for the identification of natural products targeting aminoacyl-tRNA synthetases.

Post-transfer editing by a eukaryotic leucyl-tRNA synthetase resistant to the broad-spectrum drug AN2690

2010 ◽  
Vol 430 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Xiao-Long Zhou ◽  
Min Tan ◽  
Meng Wang ◽  
Xin Chen ◽  
En-Duo Wang
Keyword(s):  
Broad Spectrum ◽  
Homo Sapiens ◽  
Functional Divergence ◽  
Specific Inhibitor ◽  
Trna Synthetase ◽  
Aquifex Aeolicus ◽  
Trna Synthetases ◽  
Aspartate Residue

Some aaRSs (aminoacyl-tRNA synthetases) develop editing mechanisms to correct mis-charged tRNA. The CP1 (connective peptide 1) domain of LeuRS (leucyl-tRNA synthetase) contains the editing active site, which is the proven target for the broad-spectrum drug AN2690 (5-fluoro-1,3-dihydro-1-hydroxy-2,1-benzoxaborole). The ESI (eukarya-specific insertion 1) in the CP1 domain of GlLeuRS (Giardia lamblia LeuRS) has been identified. Similar substitution with the ESI from HsLeuRS (Homo sapiens LeuRS) impeded the leucine activation, aminoacylation and post-transfer editing of the enzyme, but had no effect on the editing specificity toward non-specific amino acids. Thr341 in GlLeuRS served as a specificity discriminator, as found in other LeuRS systems, although its substitution with an alanine residue did not destroy Leu-tRNALeu synthesis in vitro and in vivo. The Arg338 was crucial for tRNALeu charging and the Asp440 was crucial for leucine activation and aminoacylation. The post-transfer editing required the CTD (C-terminal domain), Arg338 and Asp440 of GlLeuRS. Interestingly, GlLeuRS was completely resistant to the AN2690, which is an inhibitor of various LeuRSs. The universally conserved aspartate residue in the LeuRS CP1 domains was responsible for the resistance of GlLeuRS and another recently reported AN2690-resistant AaLeuRS (Aquifex aeolicus LeuRS). Our results indicate the functional divergence of some absolutely conserved sites, improve the understanding of the editing function of eukaryotic/archaeal LeuRSs and shed light on the development of a GlLeuRS-specific inhibitor for the treatment of giardiasis.

Sign in / Sign up

Export Citation Format

Share Document