scholarly journals The veterinary anti-parasitic selamectin is a novel inhibitor of the mycobacterial DprE1 enzyme

2021 ◽  
Author(s):  
José Manuel Ezquerra-Aznárez ◽  
Giulia Degiacomi ◽  
Henrich Gašparovič ◽  
Giovanni Stelitano ◽  
José Camilla Sammartino ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Point Mutations ◽  
Anthelmintic Activity ◽  
Docking Studies ◽  
Metabolic Labeling ◽  
Mycobacterial Species ◽  
Macrocyclic Lactones ◽  
Biochemical Assays ◽  
Mutant Strains

AbstractAvermectins are macrocyclic lactones with anthelmintic activity. Recently, they were found to be effective against Mycobacterium tuberculosis, which accounts for one third of the worldwide deaths from antimicrobial resistance. However, their anti-mycobacterial mode of action remains to be elucidated. The activity of selamectin was determined against a panel of M. tuberculosis mutants. Two strains carrying mutations in DprE1, the decaprenylphosphoryl-β-D-ribose oxidase involved in the synthesis of mycobacterial arabinogalactan, were more susceptible to selamectin. Biochemical assays against the Mycobacterium smegmatis DprE1 protein confirmed this finding, and docking studies predicted a binding site in a loop that included Leu275. Sequence alignment revealed variants in this position among mycobacterial species, with the size and hydrophobicity of the residue correlating with their MIC values; M. smegmatis DprE1 variants carrying these point mutations validated the docking predictions. However, the correlation was not confirmed when M. smegmatis mutant strains were constructed and MIC phenotypic assays performed. Likewise, metabolic labeling of selamectin-treated M. smegmatis and M. tuberculosis cells with 14C-labeled acetate did not reveal the expected lipid profile associated with DprE1 inhibition. Together, our results confirm the in vitro interactions of selamectin and DprE1 but suggest that selamectin could be a multi-target anti-mycobacterial compound.

scholarly journals The Veterinary Anti-Parasitic Selamectin Is a Novel Inhibitor of the Mycobacterium tuberculosis DprE1 Enzyme

2022 ◽  
Vol 23 (2) ◽  
pp. 771
Author(s):  
José Manuel Ezquerra-Aznárez ◽  
Giulia Degiacomi ◽  
Henrich Gašparovič ◽  
Giovanni Stelitano ◽  
Josè Camilla Sammartino ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Point Mutations ◽  
Anthelmintic Activity ◽  
Docking Studies ◽  
Metabolic Labeling ◽  
Biochemical Assays ◽  
Mutant Strains ◽  
In Vitro Interactions

Avermectins are macrocyclic lactones with anthelmintic activity. Recently, they were found to be effective against Mycobacterium tuberculosis, which accounts for one third of the worldwide deaths from antimicrobial resistance. However, their anti-mycobacterial mode of action remains to be elucidated. The activity of selamectin was determined against a panel of M. tuberculosis mutants. Two strains carrying mutations in DprE1, the decaprenylphosphoryl-β-D-ribose oxidase involved in the synthesis of mycobacterial arabinogalactan, were more susceptible to selamectin. Biochemical assays against the Mycobacterium smegmatis DprE1 protein confirmed this finding, and docking studies predicted a binding site in a loop that included Leu275. Sequence alignment revealed variants in this position among mycobacterial species, with the size and hydrophobicity of the residue correlating with their MIC values; M. smegmatis DprE1 variants carrying these point mutations validated the docking predictions. However, the correlation was not confirmed when M. smegmatis mutant strains were constructed and MIC phenotypic assays performed. Likewise, metabolic labeling of selamectin-treated M. smegmatis and M. tuberculosis cells with 14C-labeled acetate did not reveal the expected lipid profile associated with DprE1 inhibition. Together, our results confirm the in vitro interactions of selamectin and DprE1 but suggest that selamectin could be a multi-target anti-mycobacterial compound.

scholarly journals The Redox Cofactor F420Protects Mycobacteria from Diverse Antimicrobial Compounds and Mediates a Reductive Detoxification System

2016 ◽  
Vol 82 (23) ◽  
pp. 6810-6818 ◽  
Author(s):  
Thanavit Jirapanjawat ◽  
Blair Ney ◽  
Matthew C. Taylor ◽  
Andrew C. Warden ◽  
Shahana Afroze ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Mycobacterium Smegmatis ◽  
Antimicrobial Compounds ◽  
Loss Of Function ◽  
Detoxifying Enzymes ◽  
Content Type ◽  
Wide Range ◽  
Detoxification System ◽  
Mutant Strains

ABSTRACTA defining feature of mycobacterial redox metabolism is the use of an unusual deazaflavin cofactor, F420. This cofactor enhances the persistence of environmental and pathogenic mycobacteria, including after antimicrobial treatment, although the molecular basis for this remains to be understood. In this work, we explored our hypothesis that F420enhances persistence by serving as a cofactor in antimicrobial-detoxifying enzymes. To test this, we performed a series of phenotypic, biochemical, and analytical chemistry studies in relation to the model soil bacteriumMycobacterium smegmatis. Mutant strains unable to synthesize or reduce F420were found to be more susceptible to a wide range of antibiotic and xenobiotic compounds. Compounds from three classes of antimicrobial compounds traditionally resisted by mycobacteria inhibited the growth of F420mutant strains at subnanomolar concentrations, namely, furanocoumarins (e.g., methoxsalen), arylmethanes (e.g., malachite green), and quinone analogues (e.g., menadione). We demonstrated that promiscuous F420H2-dependent reductases directly reduce these compounds by a mechanism consistent with hydride transfer. Moreover,M. smegmatisstrains unable to make F420H2lost the capacity to reduce and detoxify representatives of the furanocoumarin and arylmethane compound classes in whole-cell assays. In contrast, mutant strains were only slightly more susceptible to clinical antimycobacterials, and this appeared to be due to indirect effects of F420loss of function (e.g., redox imbalance) rather than loss of a detoxification system. Together, these data show that F420enhances antimicrobial resistance in mycobacteria and suggest that one function of the F420H2-dependent reductases is to broaden the range of natural products that mycobacteria and possibly other environmental actinobacteria can reductively detoxify.IMPORTANCEThis study reveals that a unique microbial cofactor, F420, is critical for antimicrobial resistance in the environmental actinobacteriumMycobacterium smegmatis. We show that a superfamily of redox enzymes, the F420H2-dependent reductases, can reduce diverse antimicrobialsin vitroandin vivo.M. smegmatisstrains unable to make or reduce F420become sensitive to inhibition by these antimicrobial compounds. This suggests that mycobacteria have harnessed the unique properties of F420to reduce structurally diverse antimicrobials as part of the antibiotic arms race. The F420H2-dependent reductases that facilitate this process represent a new class of antimicrobial-detoxifying enzymes with potential applications in bioremediation and biocatalysis.

The anthelmintic activity of 1,10-phenanthroline, a metalloenzyme inhibitor

2019 ◽  
Author(s):  
S.M.A. Abidi ◽  
Kavita Singh ◽  
A. Rehman ◽  
R. Ullah ◽  
L. Rehman ◽  
...  
Keyword(s):  
Enzyme Inhibitor ◽  
Anthelmintic Activity ◽  
In Vivo Studies ◽  
Parasitic Helminths ◽  
Tegumental Surface ◽  
Biochemical Assays ◽  
Direct Exposure ◽  
Surface Changes

Paramphistomosis is a chronic, debilitating parasitic disease of livestock prevalent in the tropical and sub-tropical countries. Globally there is a heavy reliance on anthelmintics but concerns over drug resistance encourage the search for new leads. Metalloproteinases play a significant role in the biology and life cycle of parasitic helminths. The efficacy of metalloproteinase inhibitor, 1,10-Phenanthroline (1,10-phe) which is commonly used as a specific enzyme inhibitor in biochemical assays, was tested in vitro on Gigantocotyle explanatum tegument as a marker of anthelmintic action. The scanning electron microscopy revealed that the tegumental surface exhibited considerable changes in the worms treated with the metalloenzyme inhibitor, 1,10-phe. The untreated control worms appeared normal showing smooth tegumental surface with abundant dome shaped papillae in the anterior to mid region, while their density was less around the acetabulum which serves as a hold-fast organ helping the worms to remain attached in biliary passage. The 1,10-phe produced significant tegumental damage when the liver amphistomes were in vitro exposed to this compound at 12.5 µM concentration. The surface changes appeared in the form of edematous ridges with prominent furrows and erosion of the dome shaped papillae with rosette shaped deep lesions as a result of which deep parenchymatous tissues were exposed. The collapse of sensory bulbs as well as sloughing of tegument, particularly in the anterior-mid region was observed. The nature of damage could be comparable to various anthelmintics used in previous studies. To the best of our knowledge this is the first report of direct exposure of amphistome worms to zinc metallo-enzyme inhibitor, however, further in vivo studies are required to ascertain the anthelmintic efficacy of 1,10-phe.

scholarly journals Two New Point Mutations at A2062 Associated with Resistance to 16-Membered Macrolide Antibiotics in Mutant Strains ofMycoplasma hominis

2001 ◽  
Vol 45 (10) ◽  
pp. 2958-2960 ◽  
Author(s):  
Pio Maria Furneri ◽  
Giancarlo Rappazzo ◽  
Maria Pia Musumarra ◽  
Patrizia Di Pietro ◽  
Lucrezia S. Catania ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Mycoplasma Hominis ◽  
23S Rrna ◽  
Macrolide Antibiotics ◽  
Rrna Gene ◽  
In Vitro Exposure ◽  
Mutant Strains ◽  
23S Rrna Gene

ABSTRACT We describe two mutants of Mycoplasma hominis PG-21 which show resistance to 16-membered macrolides but susceptibility to lincosamides, obtained by in vitro exposure to increasing doses of josamycin. The 23S rRNA gene showed that each had a mutation (A2062G and A2062T) corresponding to nucleotide 2062 in Escherichia coli, which was associated with the acquired phenotype.

scholarly journals Identification of amino acid changes affecting yeast uroporphyrinogen decarboxylase activity by sequence analysis of hem12 mutant alleles

1992 ◽  
Vol 288 (3) ◽  
pp. 753-757 ◽  
Author(s):  
A Chelstowska ◽  
T Zoladek ◽  
J Garey ◽  
J Kushner ◽  
J Rytka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Point Mutations ◽  
Decarboxylase Activity ◽  
Uroporphyrinogen Decarboxylase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Active Centre ◽  
Nonsense Mutations ◽  
Mutant Strains ◽  
Leaky Mutants

The molecular basis of the uroporphyrinogen decarboxylase defect in eleven yeast ‘uroporphyric’ mutants was investigated. Uroporphyrinogen decarboxylase, an enzyme of the haem-biosynthetic pathway, catalyses the decarboxylation of uroporphyrinogen to coproporphyrinogen and is encoded by the HEM12 gene in the yeast Saccharomyces cerevisiae. The mutations were identified by sequencing the mutant hem12 alleles amplified in vitro from genomic DNA extracted from the mutant strains. Four mutations leading to the absence of enzyme protein were found: one mutation caused the substitution of the translation initiator Met to Ile, a two-base deletion created a frameshift at codon 247 and two nonsense mutations were found at codons 50 and 263. Four different point mutations were identified in seven ‘leaky’ mutants with residual modified uroporphyrinogen decarboxylase activity; each of three mutations was found in two independently isolated mutants. The nucleotide transitions resulted in the amino acid substitutions Ser-59 to Phe, Thr-62 to Ile, Leu-107 to Ser, or Ser-215 to Asn, all located in or near highly conserved regions. The results suggest that there is a single active centre in uroporphyrinogen decarboxylase, the geometry of which is affected in the mutant enzymes.

scholarly journals LEAD MOLECULE IDENTIFICATION FROM VITEX TRIFOLIA LINN FOR HELMINTHIASIS USING IN VITRO AND IN SILICO METHODS

2020 ◽  
pp. 95-103
Author(s):  
SOUNDARARAJAN MUTHUKRISHNAN ◽  
RAGUNATH G. ◽  
BLESSY SUSAN VARGHESE
Keyword(s):  
Binding Energy ◽  
In Silico ◽  
Anthelmintic Activity ◽  
Petri Dish ◽  
Docking Studies ◽  
Diffusion Method ◽  
Organ Bath ◽  
Active Constituents ◽  
Intermolecular Energy

Objective: The study was an attempt to discover a lead molecule to treat helminthiasis using Vitex trifolia. Linn (V. folia Linn) through sterile effect, in vitro and in silico evaluation. Methods: The antibacterial activity was done by Kirby-Bauer disc diffusion method in three different concentrations of extract and in vitro anthelmintic activity was carried out by petri dish and organ bath method. Further, the in silico docking studies were carried out by 11 phytoconstituents against phosphoethanolamine methyltransferase (4FGZ) using Auto Dock 4.2, it was working based on the principle of Lamarckian genetic algorithm. In docking studies, three important parameters such as binding energy, inhibition constant and intermolecular energy are determined. Results: The extracts showed an antibacterial effect in three different concentrations. At 16 mcg/disc a significant effect was observed when compared to blank and ciprofloxacin 5 mcg/disc. The anthelmintic activity in the petri dish method, means paralyzing time of Pheretimaposthuma with the dose of 25, 50 and 100 mg/ml were 13.78, 5.79 and 4.57 min respectively and Piperazine citrate (10 mg/ml) showed paralysis in 21.58 min. In the organ bath method, the time for paralysis of the worm was recorded on a slow-moving Sherrington rotating drum and the study report showed that paralyzing time was decreased at increasing concentrations of the extract. The results of in silico studies exhibited a binding energy of-10.25kcal/mol, inhibitory constant (Ki) 30.91nM, intermolecular energy,-10.84kcal/mol for abietatriene-3-ol which is lesser than the standard ligand phosphoethanolamine (-6.03kcal/mol, 38.29µM,-7.82kcal/mol) respectively. Conclusion: The study reports conclude that the active constituents in V. folia Linn having better anthelmintic activity, thus the active constituents may be optimized and make way to a new moiety for the treatment of helminthiasis.

scholarly journals In- vitro Pharmacological investigation and Molecular Docking validation of Rhodiola rosea root against Bacterial and Helminthiasis infections

2021 ◽  
Vol 12 (2) ◽  
pp. 1086-1094
Author(s):  
Syeda Sanobar ◽  
Dharmendra Ahuja
Keyword(s):  
Antibacterial Activity ◽  
Molecular Docking ◽  
Binding Energy ◽  
Bioactive Compounds ◽  
Anthelmintic Activity ◽  
Docking Studies ◽  
Rhodiola Rosea ◽  
Antibacterial Protein ◽  
Protein Target

The present study's objective was to identify the phytoconstituents present in methanolic extract of Rhodiola rosea (R. rosea) with a help of Gas chromatography-Mass Spectrometry (GC-MS). The extract was subjected for the antibacterial (Escherichia coli ) and anthelmintic (adult Indian earthworms-Pheretima posthuma)in-vitro activities followed by the validation of the same by subjecting the bioactive compounds obtained in GCMS analysis to molecular docking studies for anthelmintic and antibacterial protein targets. Six compounds with molecular formula  C12H14O4NF3,  C9H14O2Si, C29H44O12,  C18H30O, C12H23O2N, and C17H32O  were identified in GCMS analysis. Different extract concentrations viz 50, 75, 100, 150, and 200 mg/ml and 50, 75, 100, 150, and 200 µg/ml for anthelmintic activity and anti-bacterial activity respectively. For anthelmintic protein target, results of molecular docking (presented by 3D & 2D model) revealed that the identified compounds (binding energy -6.05 to -8.40 Kcal/mol) exhibited a comparable binding affinity as that of albendazole(binding energy -9.54 Kcal/mol) except C3 (binding energy +33.42 Kcal/mol) compound.  antibacterial protein target, compounds' binding affinities were found to be in the range -4.49 to -6.68 Kcal/mol, while chlorobiocin was found to be -4.75 Kcal/mol. The extract exhibited dose-dependent in-vitroanthelmintic (150 and 200 mg/ml) and antibacterial activity (150 and 200 µg/ml. The minimum lethal amount of extract concentration for anthelmintic activity was found to be 150 μg/ml. At this concentration, Pheretimaposthuma died in 33.56 ± 2.15 min while with a standard dose of albendazole, the lethal time was found to be 22.75 ± 1.63 min. Finally concluded that the identified bioactive compounds from R. rosea have the potential anthelmintic and antibacterial activity as justified by in-vitro biological evaluations and molecular docking studies.

scholarly journals Design and synthesis of new 3-((7-chloroquinolin-4-yl)amino)thiazolidin-4-one analogs as Mycobacterium tuberculosis DNA gyrase inhibitors

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Preeti S. Salve ◽  
Prajakta Parchure ◽  
Lisel Araujo ◽  
Rohini S. Kavalapure ◽  
Sunil S. Jalalpure ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Dna Gyrase ◽  
Docking Studies ◽  
Human Populations ◽  
Antitubercular Agents ◽  
Major Health ◽  
Design And Synthesis ◽  
Gyrase Inhibitors

Abstract Background Tuberculosis is evidently a major health threat among human populations worldwide. The current study presents the synthesis of new 3-((7-chloroquinolin-4-yl)amino)thiazolidin-4-one analogs (4a–o) as potential Mycobacterium tuberculosis DNA gyrase inhibitors. DNA gyrase regulates DNA topology in MTB and has been a target of choice for antibacterial therapy. With this in mind, the synthesized derivatives (4a–o) were subjected to in vitro antitubercular evaluation by the MABA method and were tested for MTB DNA gyrase inhibition by supercoiling assay. Results All the synthesized compounds displayed inhibition of MTB within the MIC range of 1.56–12.5 μM. Further, out of the selected compounds that underwent DNA gyrase inhibition, compound 4o proved to be a potent lead molecule by displaying 82% of enzyme inhibition at 1 μM. All the synthesized derivatives also underwent molecular docking studies to comprehend their hypothetical binding interactions with Mycobacterium smegmatis GyrB. Conclusion All the results suggested that most of the synthesized derivatives inhibited Mycobacterium tuberculosis, and some 3-((7-chloroquinolin-4-yl)amino)thiazolidin-4-one analogs could act as leads for the development of antitubercular agents.

Design, Synthesis and Pharmacological Evaluation of New Thiazole Derivatives as Anthelmintic Agents

2020 ◽  
Vol 13 (5) ◽  
pp. 5075-5081
Author(s):  
Sirisha Kalam ◽  
Sai Krishn G ◽  
Kumara Swamy D ◽  
Sai Santhoshi K ◽  
Durga Prasad K
Keyword(s):  
Anthelmintic Activity ◽  
Docking Studies ◽  
Molecular Property ◽  
Thiazole Derivatives ◽  
Pharmacological Agents ◽  
Design Synthesis ◽  
Standard Drug ◽  
Lipinski’S Rule ◽  
Mass Spectral ◽  
Tubulin Protein

Pharmacological agents that kills parasites are essential drugs in some tropical countries. In this study, a series of 2-amino substituted 4-phenyl thiazole derivatives (4a-e) have been synthesized by the conventional method. The thiazole derivatives were synthesized by three steps. The obtained five derivatives were purified by recrystallization using methanol as a solvent or column chromatography. They were characterized by melting point, TLC, FTIR, 1H NMR and MASS spectral data. Compounds 4a-e were evaluated in silico by using different software’s (Lipinski’s Rule of 5, OSIRIS molecular property explorer, Molsoft molecular property explorer, and PASS & docking studies). These compounds were then evaluated for their possible anthelmintic activity against Indian adult earth worms (Pherituma postuma). All the compounds displayed significant anthelmintic activity. Compound 4c and 4e were more potent compounds when compared with the standard drug (mebendazole). Molecular docking studies guided and proved the biological activity against beta tubulin protein (1OJ0). In conclusions, these new molecules have promising potential as anthelmintic for treatment of parasites.   

α-Glucosidase Inhibition and Docking Studies of 5-Deoxyflavonols and Dihydroflavonols Isolated from Abutilon pakistanicum

2019 ◽  
Vol 23 (17) ◽  
pp. 1857-1866
Author(s):  
Munawar Hussain ◽  
Zaheer Ahmed ◽  
Shamsun N. Khan ◽  
Syed A. A. Shah ◽  
Rizwana Razi ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Docking Studies ◽  
Hydroxyl Group ◽  
Coumaric Acid ◽  
In Vitro Activity ◽  
Aerial Parts ◽  
First Time ◽  
Acid Esters ◽  
Phenol Moiety

Three new 5-deoxyflavonoid and dihydroflavonoids 2, 3 and 4 have been isolated from the methanolic extract of Abutioln pakistanicum aerial parts, for which structures were elucidated explicitly by extensive MS- and NMR-experiments. In addition to these, 3,7,4′-trihydroxy-3′-methoxy flavonol (1) is reported for the first time from Abutioln pakistanicum. Compound 2 and 4 are p-coumaric acid esters while compounds 2–4 exhibited α-glucosidase inhibitory activity. Docking studies indicated that the ability of flavonoids 2, 3 and 4 to form multiple hydrogen bonds with catalytically important residues is decisive hence is responsible for the inhibition activity. The docking results signified the observed in-vitro activity quite well which is in accordance with previously obtained conclusion that phenol moiety and hydroxyl group are critical for the inhibition of α-glucosidase enzyme.

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