Mode of Action of Linenscin OC2 againstListeria innocua

1998 ◽  
Vol 64 (9) ◽  
pp. 3416-3421 ◽  
Author(s):  
Catherine Boucabeille ◽  
Lucienne Letellier ◽  
Jean-Marc Simonet ◽  
Gilles Henckes
Keyword(s):  
Mode Of Action ◽  
Cytoplasmic Membrane ◽  
Environmental Parameters ◽  
Low Doses ◽  
Gram Positive Bacteria ◽  
Hydrocarbon Chains ◽  
Energetic State ◽  
Outer Membrane Permeability ◽  
Hydrolysis Of ◽  
Small Hydrophobic

ABSTRACT Linenscin OC2 is a small hydrophobic substance produced by the orange cheese coryneform bacterium Brevibacterium linensOC2. Linenscin OC2 inhibits growth of gram-negative bacteria with an altered outer membrane permeability and gram-positive bacteria. It is also able to lyse eucaryotic cells. The mode of action of linenscin OC2 on the Listeria innocua cytoplasmic membrane and the effects of environmental parameters were investigated. Addition of low doses of linenscin OC2 resulted in an immediate perturbation of the permeability properties of the cytoplasmic membrane and of the bacterial energetic state. Linenscin OC2 induced a loss of cytoplasmic potassium, depolarization of the cytoplasmic membrane, complete hydrolysis of internal ATP, efflux of inorganic phosphate, and transient increase in oxygen consumption. Potassium loss occurred in the absence of a proton motive force and was severely reduced at low temperatures, presumably as a result of increased ordering of the lipid hydrocarbon chains of the cytoplasmic membrane. We propose that linenscin OC2 interacts with the cytoplasmic membrane and that the permeability changes observed at low doses reflect the formation of pore-like structures in this membrane.

scholarly journals Antimicrobial Activity and Mode of Action of Celastrol, a Nortriterpen Quinone Isolated from Natural Sources

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 591
Author(s):  
Nayely Padilla-Montaño ◽  
Leandro de León Guerra ◽  
Laila Moujir
Keyword(s):  
Antimicrobial Activity ◽  
Cytoplasmic Membrane ◽  
Bactericidal Effect ◽  
Inoculum Size ◽  
Bacterial Populations ◽  
Gram Positive Bacteria ◽  
Dna And Rna ◽  
Dna And Rna Synthesis ◽  
Natural Derivative ◽  
Interesting Alternative

Species of the Celastraceae family are traditionally consumed in different world regions for their stimulating properties. Celastrol, a triterpene methylene quinone isolated from plants of celastraceas, specifically activates satiety centers in the brain that play an important role in controlling body weight. In this work, the antimicrobial activity and mechanism of action of celastrol and a natural derivative, pristimerin, were investigated in Bacillus subtilis. Celastrol showed a higher antimicrobial activity compared with pristimerin, being active against Gram-positive bacteria with minimum inhibitory concentrations (MICs) that ranged between 0.16 and 2.5 µg/mL. Killing curves displayed a bactericidal effect that was dependent on the inoculum size. Monitoring of macromolecular synthesis in bacterial populations treated with these compounds revealed inhibition in the incorporation of all radiolabeled precursors, but not simultaneously. Celastrol at 3 µg/mL and pristimerin at 10 µg/mL affected DNA and RNA synthesis first, followed by protein synthesis, although the inhibitory action on the uptake of radiolabeled precursors was more dramatic with celastrol. This compound also caused cytoplasmic membrane disruption observed by potassium leakage and formation of mesosome-like structures. The inhibition of oxygen consumption of whole and disrupted cells after treatments with both quinones indicates damage in the cellular structure, suggesting the cytoplasmic membrane as a potential target. These findings indicate that celastrol could be considered as an interesting alternative to control outbreaks caused by spore-forming bacteria.

scholarly journals Study of the mode of action of a polygalacturonase from the phytopathogen Burkholderia cepacia

2007 ◽  
Vol 407 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Claudia Massa ◽  
Mads H. Clausen ◽  
Jure Stojan ◽  
Doriano Lamba ◽  
Cristiana Campa
Keyword(s):  
Mode Of Action ◽  
Burkholderia Cepacia ◽  
Time Course ◽  
Glycoside Hydrolase Family ◽  
Enzymatic Mechanism ◽  
Processive Enzyme ◽  
Chain Lengths ◽  
Methylation Patterns ◽  
Hydrolysis Of ◽  
Hydrolase Family

We have recently isolated and heterologously expressed BcPeh28A, an endopolygalacturonase from the phytopathogenic Gram-negative bacterium Burkholderia cepacia. Endopolygalacturonases belong to glycoside hydrolase family 28 and are responsible for the hydrolysis of the non-esterified regions of pectins. The mode of action of BcPeh28A on different substrates has been investigated and its enzymatic mechanism elucidated. The hydrolysis of polygalacturonate indicates that BcPeh28A is a non-processive enzyme that releases oligomers with chain lengths ranging from two to eight. By inspection of product progression curves, a kinetic model has been generated and extensively tested. It has been used to derive the kinetic parameters that describe the time course of the formation of six predominant products. Moreover, an investigation of the enzymatic activity on shorter substrates that differ in their overall length and methylation patterns sheds light on the architecture of the BcPeh28A active site. Specifically the tolerance of individual sites towards methylated saccharide units was rationalized on the basis of the hydrolysis of hexagalacturonides with different methylation patterns.

scholarly journals The Phosphoenolpyruvate:Sugar Phosphotransferase System Is Involved in Sensitivity to the Glucosylated Bacteriocin Sublancin

2015 ◽  
Vol 59 (11) ◽  
pp. 6844-6854 ◽  
Author(s):  
C. V. Garcia De Gonzalo ◽  
E. L. Denham ◽  
R. A. T. Mars ◽  
J. Stülke ◽  
W. A. van der Donk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Mechanism Of Action ◽  
Mode Of Action ◽  
Phosphotransferase System ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Distinct Mechanism ◽  
Genomic Studies ◽  
Increased Sensitivity ◽  
Bacterial Sensitivity

ABSTRACTThe mode of action of a group of glycosylated antimicrobial peptides known as glycocins remains to be elucidated. In the current study of one glycocin, sublancin, we identified the phosphoenolpyruvate:sugar phosphotransferase system (PTS) ofBacillusspecies as a key player in bacterial sensitivity. Sublancin kills several Gram-positive bacteria, such asBacillusspecies andStaphylococcus aureus, including methicillin-resistantS. aureus(MRSA). Unlike other classes of bacteriocins for which the PTS is involved in their mechanism of action, we show that the addition of PTS-requiring sugars leads to increased resistance rather than increased sensitivity, suggesting that sublancin has a distinct mechanism of action. Collectively, our present mutagenesis and genomic studies demonstrate that the histidine-containing phosphocarrier protein (HPr) and domain A of enzyme II (PtsG) in particular are critical determinants for bacterial sensitivity to sublancin.

scholarly journals Sporadic Emergence of Klebsiella pneumoniae Strains Resistant to Cefepime and Cefpirome in Greek Hospitals

1998 ◽  
Vol 36 (1) ◽  
pp. 266-268 ◽  
Author(s):  
L. S. Tzouvelekis ◽  
E. Tzelepi ◽  
E. Prinarakis ◽  
M. Gazouli ◽  
A. Katrahoura ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Membrane Permeability ◽  
Outer Membrane ◽  
Outer Membrane Permeability ◽  
Greek Hospitals ◽  
Hydrolysis Of

The sporadic emergence of Klebsiella pneumoniae strains resistant to cefepime and cefpirome was observed in Greek hospitals during 1996. Examination of six epidemiologically distinct strains and clones selected in vitro provided indications that resistance is due to the cooperation of decreased outer membrane permeability and hydrolysis of the cephalosporins by SHV-5 β-lactamase, which was produced in large amounts.

Zinc oxide microrods and nanorods: different antibacterial activity and their mode of action against Gram-positive bacteria

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 56031-56040 ◽  
Author(s):  
Ilaria Rago ◽  
Chandrakanth Reddy Chandraiahgari ◽  
Maria P. Bracciale ◽  
Giovanni De Bellis ◽  
Elena Zanni ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Mode Of Action ◽  
Gram Positive ◽  
Gram Positive Bacteria

ZnO micro and nanorods, produced through simple and inexpensive techniques, resulted to be strong antimicrobials against Gram-positive bacteria, in vitro as well as in vivo, by altering cell outer structures like membrane and exopolysaccharides.

scholarly journals Purification and characterization of ascamycin-hydrolysing aminopeptidase from Xanthomonas citri

1986 ◽  
Vol 233 (2) ◽  
pp. 459-463 ◽  
Author(s):  
H Osada ◽  
K Isono
Keyword(s):  
Antibacterial Activity ◽  
Enzyme Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Homogeneous State ◽  
Xanthomonas Citri ◽  
Gram Positive Bacteria ◽  
Xanthomonas Species ◽  
Hydrolysis Of

A nucleoside antibiotic, ascamycin (9-beta-[5′-0-(N-L-alanyl) sulphamoyl-D-ribofuranosyl]-2-chloroadenine), has a selective antibacterial activity against Xanthomonas species. When ascamycin was dealanylated, dealanylascamycin showed a broad antibacterial activity against various Gram-negative and Gram-positive bacteria. Xanthomonas citri is susceptible to ascamycin by virtue of the ascamycin-dealanylating enzyme on the cell surface [Osada & Isono (1985) Antimicrob. Agents Chemother. 27, 230-233]. The enzyme (Xc aminopeptidase) was purified from X. citri cells by successive DEAE-cellulose, chromatofocusing and Sephadex G-100 column chromatography to a homogeneous state. The purified enzyme exhibited a single band with an Mr of 38 000 in SDS/polyacrylamide-gel electrophoresis. Gel filtration on a calibrated column indicated a similar Mr value. The isoelectric point of the enzyme was 5.7. The enzyme catalysed the hydrolysis of the alanyl group of ascamycin and liberated alanine from the sulphamoyl nucleoside. The enzyme also catalysed the hydrolysis of L-proline beta-naphthylamide and L-alanine beta-naphthylamide. The optimal pH and temperature for enzyme activity were pH 7.5-8.0 and 35-40 degrees C respectively. The enzyme was inhibited by thiol-enzyme inhibitors (i.e. rho-chloromercuribenzoate and N-ethylmaleimide), but was not affected by various naturally occurring aminopeptidase inhibitors (i.e. amastatin, bestatin, pepstatin and leupeptin). Mn2+ and Mg2+ activated the enzyme, whereas Cu2+, Zn2+ and Cd2+ were inhibitory.

New Reactive Coenzyme Analogues for Affinity Labeling of NAD+ and NADP+ Dependent Dehydrogenases

1995 ◽  
Vol 50 (7-8) ◽  
pp. 476-486
Author(s):  
Reinhard Jeck ◽  
Michael Scholze ◽  
Anja Tischlich ◽  
Christoph Woenckhaus ◽  
Jürgen Zimmermann
Keyword(s):  
Adenosine Diphosphate ◽  
Competitive Inhibitor ◽  
Hydrogen Donor ◽  
Reduced Form ◽  
Irreversible Inhibitor ◽  
Hydrocarbon Chains ◽  
Phosphoric Acid Ester ◽  
Acetyl Group ◽  
Hydrolysis Of ◽  
Phosphate Groups

Abstract Reactive coenzyme analogues ω-(3-diazoniumpyridinium)alkyl adenosine diphosphate were prepared by reaction of ω-(3-aminopyridinium)alkyl adenosine diphosphate with nit­rous acid. In these compounds the nicotinamide ribose is substituted by hydrocarbon chains of varied lengths (n-ethyl to n-pentyl). The diazonium compounds are very unstable and decompose rapidly at room temperature. They show a better stability at 0 °C. L actate and alcohol dehydrogenase do not react with any of the analogues. Glyceraldehyde-3-phosphate dehydrogenase reacts rapidly with the diazonium pentyl compound. Decreasing the length of the alkyl chain significantly decreases the inactivation velocity. 3α,20β-Hydroxysteroid dehydrogenase reacts at 0 °C with the ethyl homologue and slowly with the propyl compound. The butyl-and pentyl analogues do not inactivate at 0 °C. Tests with 14C -labeled 2-(3-diazoniumpyridinium)ethyl adenosine diphosphate show that complete loss of enzyme activity results after incorporation of 2 moles of inactivator into 1 mole of tetrameric enzyme. 4-(3-Acetylpyridinium)butyl 2 ′-phospho-adenosine diphosphate, a structural analogue of NADP +, was prepared by condensation of adenosine-2,3-cyclophospho-5′-phosphomorpholidate with (3-acetylpyridinium)butyl phosphate, followed by hydrolysis of the cyclic phosphoric acid ester with 2 ′:3′-cyclonucleotide-3′-phosphodiesterase. Because of the redox potential (-315 mV) and the distance between the pyridinium and phosphate groups, this analogue is a hydrogen acceptor and its reduced form a hydrogen donor in tests with alcohol dehyd roge­nase from Thermoanaerobium brockii. The reduced form of the coenzyme analogue also is a hydrogen donor with glutathione reductase. With other NADP +-dependent dehydrogenases the com pound has been show n to be a competitive inhibitor against the natural coenzyme. The acetyl group reacts with bromine to form the bromoacetyl group. This reactive bromoacetyl analogue is a specific active-site directed irreversible inhibitor of isocitrate dehydrogenase.

scholarly journals Persistence of methylated bases in ribonucleic acid of syrian golden hamster liver after administration of dimethylnitrosamine

1979 ◽  
Vol 177 (3) ◽  
pp. 967-973 ◽  
Author(s):  
G P Margison ◽  
J M Margison ◽  
R Montesano
Keyword(s):  
Ribosomal Rna ◽  
Golden Hamster ◽  
Excision Repair ◽  
Experimental System ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Syrian Golden Hamster ◽  
Low Doses ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Of

1. Syrian golden hamster liver ribosomal RNA was isolated up to 96 h after administration of [14C]dimethylnitrosamine at 25 mg/kg or 2.5 mg/kg body weight. 2. The chemical alkyation products, 7-methylguanine, 3-methylcytosine, O6-methylguanosine and 1-methyladenosine, were measured after acidic or enzymic hydrolysis of the RNA to bases or mononucleosides followed by ion-exchange chromatography. 3. Between 7 and 96 h, the relative amounts of alkylation products did not change with time even though the absolute amounts fell by approx. 80% and 51% after the high and low doses respectively. 4. The results suggest that base specific excision repair does not exist for RNA alkylation products in this experimental system.

Mode of action of nisin on Escherichia coli

2020 ◽  
Vol 66 (2) ◽  
pp. 161-168
Author(s):  
Imelda J. Galván Márquez ◽  
Bruce McKay ◽  
Alex Wong ◽  
James J. Cheetham ◽  
Cody Bean ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mode Of Action ◽  
Genetic Interactions ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Chemical Genetic ◽  
Gram Positive Bacteria ◽  
Knockout Mutants ◽  
Membrane Envelope ◽  
Insight Into

Nisin is a class I polycyclic bacteriocin produced by the bacterium Lactococcus lactis, which is used extensively as a food additive to inhibit the growth of foodborne Gram-positive bacteria. Nisin also inhibits growth of Gram-negative bacteria when combined with membrane-disrupting chelators such as citric acid. To gain insight into nisin’s mode of action, we analyzed chemical–genetic interactions and identified nisin-sensitive Escherichia coli strains in the Keio library of knockout mutants. The most sensitive mutants fell into two main groups. The first group accords with the previously proposed mode of action based on studies with Gram-positive bacteria, whereby nisin interacts with factors involved in cell wall, membrane, envelope biogenesis. We identified an additional, novel mode of action for nisin based on the second group of sensitive mutants that involves cell cycle and DNA replication, recombination, and repair. Further analyses supported these two distinct modes of action.

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