scholarly journals Generation of Lasso Peptide-Based ClpP Binders

2021 ◽  
Vol 23 (1) ◽  
pp. 465
Author(s):  
Imran T. Malik ◽  
Julian D. Hegemann ◽  
Heike Brötz-Oesterhelt

The Clp protease system fulfills a plethora of important functions in bacteria. It consists of a tetradecameric ClpP barrel holding the proteolytic centers and two hexameric Clp-ATPase rings, which recognize, unfold, and then feed substrate proteins into the ClpP barrel for proteolytic degradation. Flexible loops carrying conserved tripeptide motifs protrude from the Clp-ATPases and bind into hydrophobic pockets (H-pockets) on ClpP. Here, we set out to engineer microcin J25 (MccJ25), a ribosomally synthesized and post-translationally modified peptide (RiPP) of the lasso peptide subfamily, by introducing the conserved tripeptide motifs into the lasso peptide loop region to mimic the Clp-ATPase loops. We studied the capacity of the resulting lasso peptide variants to bind to ClpP and affect its activity. From the nine variants generated, one in particular (12IGF) was able to activate ClpP from Staphylococcus aureus and Bacillus subtilis. While 12IGF conferred stability to ClpP tetradecamers and stimulated peptide degradation, it did not trigger unregulated protein degradation, in contrast to the H-pocket-binding acyldepsipeptide antibiotics (ADEPs). Interestingly, synergistic interactions between 12IGF and ADEP were observed.

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.


2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.


2018 ◽  
Vol 42 (10) ◽  
pp. 512-514
Author(s):  
Rui-bo Xu ◽  
Xiao-tian Yang ◽  
Hai-nan Li ◽  
Peng-cheng Zhao ◽  
Jiao-jiao Li ◽  
...  

Two new bis-Schiff bases containing a piperazine ring, N,N‘-bis(4-chlorobenzylidene)- and N,N‘-bis(4-cyanobenzylidene)-1,4-bis(3-aminopropyl)piperazine, were prepared by the reaction of N,N‘-bis(3-aminopropyl)piperazine with 4-chloro- and 4-cyanobenzaldehyde, respectively. The dichloro compound was fully identified by X-ray crystallography and it exhibited good antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis.


2020 ◽  
pp. 1-4
Author(s):  
Hatim MY Hamadnalla ◽  
◽  
Mahdi Abd Elmageed Mohammed ◽  

The objective of this study to examine phytochemical analysis of sonchus oleraceus l, (asteraceae) (moliata) extracts which were extracted by four solvents, petroleum ether, chloroform, methanol and distill water and to assess their potential antibacterial against four standard bacteria gram-positive and gramnegative (bacillus subtilis staphylococcus aureu, salmonella typhi, and pscudomona aeruginosa) and antioxidant activities. (moliata) extracts using cold maceration method to extract sonchus oleraceus l, (asteraceae) locally known as (moliata) extracts, where dpph assay and paper disc diffusion assay were employed to evaluate the antioxidant and antibacterial activities respectively. The results showed that tannins, triterpenes, a sterols, flavonoids and cardiac glycosides compounds were present in the sonchus oleraceus l, (asteraceae) lives (moliata) extracts. The methanol extract of leaves showed high antioxidant potential (77± 0.03 % ) and chloroform showed low antioxidant potential activity (4±0.09) compare with propyl gallate as standard (93± 0.010 %) against dpph. Chloroform extract was effective and give moderate zone of inhibition against staphylococcus aureus. Methanol extract was effective and showed moderate zone of inhibition against staphylococcus aureus, bacillus subtilis, salmonella typhi and pseudomonas aeruginosa.


Author(s):  
Umeh Odera Richard ◽  
E. I. Chukwura ◽  
Ibo Eziafakaego Mercy

A fish pond with recommended water quality will produce healthy fishes. Fish ponds with poor water quality will cause fish mortality and outbreak of diseases to fish consumers. Physicochemical analysis was done using standard analytical methods, the total bacterial count was determined by dilution and membrane filtration techniques. Parasitological analysis was done using the centrifugation method. A total of fifteen well waters were sampled during wet season. Results showed that the temperature ranged from 27°C to 29°C, pH, 6.21 to 8.15; dissolved oxygen, 4.28 mg/l to 5.78 mg/l, electrical conductivity, 166.36 µs/cm to 394.00 µs/cm; total dissolved solids, 41 mg/l to 121 mg/l; total suspended solids, 1.00 mg/l to 19.40 mg/l; total solids, 42.00 mg/l to 140.4 mg/l; turbidity values, 7.01 NTU to 10.36 NTU; nitrate, 3.10 mg/l to 28.00 mg/l; total alkalinity, 36 mg/l to 91 mg/l; phosphate, 1.26 mg/l to 13.11 mg/l; sulphate, 0.39 mg/l to 4.37 mg/l; total chloride, 7.08 mg/l to 14.19 mg/l; carbonates, 1.33 mg/l to 2.35 mg/l; bicarbonates, 34.59 mg/l to 89.38 mg/l; total hardness, 25.31 mg/l to 53.04 mg/l; calcium hardness, 23.94 mg/l to 51.96 mg/l; magnesium hardness, 1.08 mg/l to 4.20 mg/l; total acidity, 2 mg/l to 22 mg/l; potassium, 0.04 mg/l to 2.23 mg/l; cadmium, 0.00 mg/l to 0.04 mg/l; lead, 0.01 mg/l - 0.16 mg/l; chromium, 0.00 mg/l - 0.03 mg/l; mercury was not detected, copper, 0.00 mg/l - 0.04 mg/l; arsenic, 0.00 mg/l - 0.02 mg/l; zinc, 0.00 mg/l to 0.02 mg/l; iron, 0.01 mg/l - 1.19 mg/l. The total bacterial counts ranged from 3.60-4.12 log cfu/ml; total coliforms, 14-46 cfu/100ml, Vibrio cholerae, 0-11 cfu/100ml; Vibrio parahaemolyticus, 0-15 cfu/100ml; faecal coliform, 1-9 cfu/100 ml; Acinetobacter calcoaceticus, 0-8 cfu/100 ml; Bacillus subtilis, 0-9 cfu/ml; Staphylococcus aureus, 0-5 cfu/ml; Pseudomonas aeruginosa, 0-12 cfu/100 ml; Pseudomonas fluorescens, 0-12 cfu/100 ml and Clostridium perfringens were not detected in any of the samples. Twelve bacterial species namely Klebsiella pneumoniae, Acinetobacter calcoaceticus, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Pseudomonas fluorescens, Pseudomonas aeruginosa, Proteus mirabilis, Vibrio parahaemolyticus, Bacillus subtilis, Shigella flexineri and Salmonella typhi were isolated and identified using standard analytical and molecular procedures. Parasites identified were Ichthyobodo species, Diplostomum species, Myxobolus species, Chilodonella species, Bothriocephalus species, Ambiphrya species and Leech species. Salmonella typhi had the highest frequency of isolation (20.63%) while Acinetobacter calcoaceticus and Staphylococcus aureus had the lowest frequency of isolation (2.83%). Ichthyobodo species had the highest frequency of isolation (21.43%) while Leech species had the lowest frequency of isolation (5.71%). Some of the physicochemical, bacteriological and parasitological parameters had values above World Health Organization admissible limits and therefore proper sanitary practices and water treatments must be employed to prevent epidemic among fish consumers.


Author(s):  
Nur Aishah Abdul Wahab ◽  
Hairul Shahril Muhamad ◽  
Nabilah Ahmad Alhadi ◽  
Salina Mat Radzi ◽  
Maryam Mohamed Rehan ◽  
...  

Combination effects between Cymbopogon flexuosus and Cymbopogon nardus essential oils were studied to determine whether the combination could emerge as better and more powerful antimicrobial agents against six selected bacteria includes Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis. This combination study exhibited 40.67% additive, 28.67% antagonistic, 16.00% indifferent and 14.66% synergistic effects. C. flexuosus and C. nardus essential oils in combination showed a high inhibitory activity against S. aureus with 16% synergistic, 64% additive and 20% indifferent effects.


2012 ◽  
Vol 446 (2) ◽  
pp. 311-320 ◽  
Author(s):  
Anders Tryggvesson ◽  
Frida M. Ståhlberg ◽  
Axel Mogk ◽  
Kornelius Zeth ◽  
Adrian K. Clarke

The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. In plant chloroplasts and cyanobacteria, the essential constitutive Clp protease consists of the Hsp100/ClpC chaperone partnering a proteolytic core of catalytic ClpP and noncatalytic ClpR subunits. In the present study, we have examined putative determinants conferring the highly specific association between ClpC and the ClpP3/R core from the model cyanobacterium Synechococcus elongatus. Two conserved sequences in the N-terminus of ClpR (tyrosine and proline motifs) and one in the N-terminus of ClpP3 (MPIG motif) were identified as being crucial for the ClpC–ClpP3/R association. These N-terminal domains also influence the stability of the ClpP3/R core complex itself. A unique C-terminal sequence was also found in plant and cyanobacterial ClpC orthologues just downstream of the P-loop region previously shown in Escherichia coli to be important for Hsp100 association to ClpP. This R motif in Synechococcus ClpC confers specificity for the ClpP3/R core and prevents association with E. coli ClpP; its removal from ClpC reverses this core specificity.


2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VĂN HỒNG THIỆN ◽  
LÊ BÍCH TRÂM ◽  
NGUYỄN THANH LAN ◽  
HỒ NGUYỄN HOÀNG YẾN ◽  
LƯU HỒNG TRƯỜNG ◽  
...  

Nghiên cứu này đã xác định được mẫu nghiên cứu thu tại Vườn quốc gia Phú Quốc là loài Homalomena pierreana. Thông qua kỹ thuật sắc ký ghép khối phổ, 10 hợp chất thuộc nhóm sesquiterpene có trong cao chiết ethanol của thân rễ loài H. pierreana đã được xác định. Ngoài ra, cao chiết ethanol từ mẫu nghiên cứu cũng cho thấy khả năng kháng lại 6 chủng vi khuẩn kiểm định là Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis và Salmonella typhimurium.


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