The antioxidative action of amphiphilic mono-(alkanoylamino) ethyldimethylamine-N-oxides (EDA), di-N-oxides 1,1-bis {[2-(N,N-dimethylamino)ethyl]amido}alkane-di-N-oxides (MEDA) and 1,1-bis {[3-(N,N-dimethylamino)propyl]amido}alkane-di-N-oxides (MPDA) with a 12- and 14-membered acyl chain against tert-butylhydroperoxide (TBHP)-produced peroxyl and paraquat (PQ)-generated superoxide radicals was determined in superoxide dismutase-deficient mutants of Saccharomyces cerevisiae, and, in parallel, in a chemical assay based on chemiluminescence changes caused in a luminol system by peroxyl radicals generated from the azo-compound 2,2'-azobis(2-amidinopropane dihydrochloride) (AAPH). At 30 micromol/L, the shorter-chain compounds did not affect strain survival while longer-chain ones, in some cases, lowered the survival of sod2 and sod1 sod2 cells. Whether nontoxic or medium-toxic, all N-oxides protected the sod strains against the toxic effect of PQ and TBHP, the protection being stronger with the di-N-oxides. The survival was lowered only by 14-MPDA in the TBHP-exposed sod2 mutant. Membrane lipids isolated from all strains were protected against TBHP-induced peroxidation by both mono- and di-N-oxides, the protection being dependent on the alkyl chain length. Mono-N-oxides were again less active than di-N-oxides with the same alkyl chains, the antiperoxidative activity being also dependent on lipids isolated from the individual mutants. In the chemiluminescence assay, the IC50 value of the N-oxides for scavenging of radicals generated from AAPH generally decreased (i.e. the scavenging efficiency increased) with increasing chain length and was the highest in MEDA.

• MeSH
• Amidines metabolism   MeSH
• Antioxidants pharmacology   MeSH
• Biological Assay MeSH
• Dimethylamines chemistry   pharmacology   MeSH
• Luminescence MeSH
• Luminescent Measurements MeSH
• Luminol MeSH
• Mutation * MeSH
• Oxidants metabolism   MeSH
• Peroxides pharmacology   MeSH
• Saccharomyces cerevisiae drug effects   enzymology   genetics   physiology   MeSH
• Free Radical Scavengers chemistry   pharmacology   MeSH
• Superoxide Dismutase genetics   MeSH
• tert-Butylhydroperoxide pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• 2,2'-azobis(2-amidinopropane) MeSH Browser
• Amidines MeSH
• Antioxidants MeSH
• Dimethylamines MeSH
• Luminol MeSH
• Oxidants MeSH
• perhydroxyl radical MeSH Browser
• Peroxides MeSH
• Free Radical Scavengers MeSH
• Superoxide Dismutase MeSH
• tert-Butylhydroperoxide MeSH

Two classes of newly synthesized amphiphilic compounds, phenolic antioxidants ("phenolics") and N-oxides exert in vivo antioxidant effects on live S. cerevisiae cells. Both groups have low toxicity, phenolics being more toxic than N-oxides and compounds with a longer alkyl chain having higher toxicity than those with a shorter alkyl chain. Phenolic antioxidants protect yeast cells exposed to the superoxide producer paraquat and peroxyl generator tert-butylhydroperoxide better than N-oxides at 3-fold higher concentration. Both types of antioxidants enhance the survival of pro-oxidant-exposed cells of S. cerevisiae mutants deficient in cytosolic and/or mitochondrial superoxide dismutase and could be good compounds which mimic the role of superoxide dismutases. The results of measurement of antioxidant activity in an in vitro chemiluminescence test differ from the results obtained in vivo with S. cerevisiae superoxide dismutase mutants. In contrast to their action on live cells, phenolics are less effective than N-oxides in preventing lipid peroxidation of an emulsion of lipids isolated from S. cerevisiae membranes.

• MeSH
• Amines chemistry   pharmacology   toxicity   MeSH
• Antifungal Agents toxicity   MeSH
• Antioxidants chemistry   pharmacology   toxicity   MeSH
• Gene Deletion MeSH
• Phenols chemistry   pharmacology   toxicity   MeSH
• Quaternary Ammonium Compounds chemistry   pharmacology   toxicity   MeSH
• Membrane Lipids metabolism   MeSH
• Microbial Viability MeSH
• Paraquat toxicity   MeSH
• Lipid Peroxidation MeSH
• Saccharomyces cerevisiae drug effects   MeSH
• Superoxide Dismutase genetics   MeSH
• tert-Butylhydroperoxide toxicity   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Amines MeSH
• Antifungal Agents MeSH
• Antioxidants MeSH
• Phenols MeSH
• Quaternary Ammonium Compounds MeSH
• Membrane Lipids MeSH
• Paraquat MeSH
• Superoxide Dismutase MeSH
• tert-Butylhydroperoxide MeSH

Amphiphilic 3-(alkanoylamino)propyldimethylamine-N-oxides with different length of the alkyl chain, i.e. different hydrophilic-lipophilic balance, act in micromolar concentrations as SOD mimics by lifting the inhibition of aerobic growth caused by SOD deletions in Saccharomyces cerevisiae. They also enhance the survival of sod mutants of S. cerevisiae exposed to the hydrophilic superoxide-generating prooxidant paraquat and the amphiphilic hydroperoxide-producing tert-butylhydroperoxide (TBHP), and largely prevent TBHP-induced peroxidation of isolated yeast plasma membrane lipids. Unlike the SOD-mimicking effect, the magnitude of these effects depends on the alkyl chain length of the amine-N-oxides, which incorporate into S. cerevisiae membranes, causing fluidity changes in both the hydrophilic surface part of the membrane and the membrane lipid matrix. Unlike wild-type strains, the membranes of sod mutants were found to contain polyunsaturated fatty acids; the sensitivity of the mutants to lipophilic pro-oxidants was found to increase with increasing content of these acids. sod mutants are useful in assessing pro- and antioxidant properties of different compounds.

• MeSH
• Antioxidants pharmacology   MeSH
• Dimethylamines pharmacology   MeSH
• Membrane Fluidity drug effects   MeSH
• Membrane Lipids chemistry   metabolism   MeSH
• Oxidative Stress MeSH
• Paraquat toxicity   MeSH
• Lipid Peroxidation drug effects   MeSH
• Saccharomyces cerevisiae drug effects   enzymology   MeSH
• Superoxide Dismutase chemistry   genetics   metabolism   MeSH
• tert-Butylhydroperoxide toxicity   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antioxidants MeSH
• Dimethylamines MeSH
• Membrane Lipids MeSH
• Paraquat MeSH
• Superoxide Dismutase MeSH
• tert-Butylhydroperoxide MeSH

The plasma membrane and mitochondria of bottom fermenting brewer's yeast obtained as a by-product of industrial beer production were isolated and the lipid fraction was analyzed. The phospholipid content accounted for 78 mg/g protein in the plasma membrane and 59 mg/g protein in the mitochondria. Major phospholipids in both preparations were phosphatidylinositol, phosphatidylcholine and phosphatidylethanolamine but their proportions differed significantly. In the plasma membrane phosphatidylinositol, and in the mitochondria phosphatidylcholine were present in the highest concentration (37 and 30%, respectively). The main classes of neutral lipids (triacylglycerols, ergosterol, squalene and steryl esters) were twice more abundant in the plasma membrane than in the mitochondria (61 and 33 mg/g protein, respectively). A characteristic of the neutral lipid composition of both organelles was the low content of ergosterol (12 and 7 mg/g protein, respectively) and a high content of squalene (25 and 22 mg/g protein). The main feature of the fatty acid composition of both organelles was the preponderance of saturated fatty acids (78 and 79%, respectively), among which palmitic acid was the principal one. The most expressed characteristics of lipid fractions of the analyzed plasma membranes and mitochondria, high concentration of squalene and preponderance of saturated fatty acids are the consequences of anaerobic growth conditions. The lack of oxygen had possibly the strongest effect on the lipid composition of the plasma membranes and mitochondria of bottom fermenting brewer's yeast.

• MeSH
• Cell Membrane chemistry   MeSH
• Chromatography, Gas MeSH
• Phospholipids analysis   isolation & purification   MeSH
• Fatty Acids analysis   isolation & purification   MeSH
• Membrane Lipids analysis   isolation & purification   MeSH
• Mitochondria chemistry   MeSH
• Saccharomyces cerevisiae chemistry   MeSH
• Squalene analysis   isolation & purification   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Phospholipids MeSH
• Fatty Acids MeSH
• Membrane Lipids MeSH
• Squalene MeSH

The long-term action of recommended (RC) and near-recommended concentrations of several commercial biocides (Lonzabac 12.100, Genamin CS302D, benzalkonium chloride and 2-phenoxyethanol) on cells of S. cerevisiae wild-type strain DTXII was described using plating tests while short-term effects were determined using the potentiometric fluorescent probe diS-C3(3) that detects both changes in membrane potential and impairment of membrane integrity. A 2-d plating of cells exposed to 0.5xRC of benzalkonium chloride and Genamin CS302D for 15 min showed a complete long-term cell killing, with 2-phenoxyethanol the killing was complete only at 2xRC and Lonzabac caused complete killing at RC but not at 0.5xRC. The diS-C3(3) fluorescence assay performed immediately after a 10-min biocide exposure revealed several concentration-dependent modes of action: Lonzabac at 0.5xRC caused a mere depolarization, higher concentrations causing gradually increasing cell damage; benzalkonium chloride and Genamin CS302D rapidly damaged the membrane of some cells and depolarized the rest whereas 2-phenoxyethanol, which had the lowest effect in the plating test, produced a concentration-dependent fraction of cells with impaired membranes. Cell staining slightly increased during the diS-C3(3) assay; addition of a protonophore showed that part of the remaining undamaged cells retained their membrane potential. Comparison of short-term and long-term data implies that membrane depolarization alone is not sufficient for complete long-term killing of yeast cells under the action of a biocide unless it is accompanied by perceptible impairment of membrane integrity. The results show that the diS-C3(3) fluorescence assay, which reflects the short-term effects of a biocide on cell membranes, can be successfully used to assess the microbicidal efficiency of biocides.

• MeSH
• Anti-Infective Agents pharmacology   MeSH
• Benzalkonium Compounds pharmacology   MeSH
• Cell Membrane drug effects   MeSH
• Ethylene Glycols pharmacology   MeSH
• Fluorescent Dyes metabolism   MeSH
• Spectrometry, Fluorescence MeSH
• Carbocyanines metabolism   MeSH
• Membrane Potentials drug effects   MeSH
• Microbial Sensitivity Tests methods   MeSH
• Cell Membrane Permeability drug effects   MeSH
• Saccharomyces cerevisiae drug effects   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• 3,3'-dipropylthiacarbocyanine MeSH Browser
• Anti-Infective Agents MeSH
• Benzalkonium Compounds MeSH
• Ethylene Glycols MeSH
• Fluorescent Dyes MeSH
• Carbocyanines MeSH
• phenoxyethanol MeSH Browser

S. cerevisiae strain delta sodl lacking Cu,Zn-superoxide dismutase and delta sodl delta sod2 mutant lacking both Cu,Zn-SOD and Mn-superoxide dismutase displayed strongly reduced aerobic growth on glucose, glycerol and lactate; delta sod2 deletion had no effect on aerobic growth on glucose and largely precluded growth on glycerol and lactate. The oxygen-induced growth defects and their alleviation by antioxidants depended on growth conditions, in particular on oxygen supply to cells. Under strong aeration, vitamins A and E had a low effect, 100 mumol/L quercetin alleviated the growth defects of all three mutants while beta-carotene had no growth-restoring effect. The superoxide producer paraquat inhibited the aerobic growth of all three mutants in a concentration-dependent manner. Low concentrations of antioxidants had no effect on paraquat toxicity while higher concentrations supported the toxic effect of the agent.

• MeSH
• Antioxidants pharmacology   MeSH
• Bacteriological Techniques MeSH
• Phenotype MeSH
• Oxygen pharmacology   MeSH
• Oxidative Stress drug effects   MeSH
• Partial Pressure MeSH
• Saccharomyces cerevisiae drug effects   genetics   metabolism   MeSH
• Superoxide Dismutase-1 MeSH
• Superoxide Dismutase genetics   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antioxidants MeSH
• Oxygen MeSH
• Superoxide Dismutase-1 MeSH
• Superoxide Dismutase MeSH
• superoxide dismutase 2 MeSH Browser

Damage caused to Saccharomyces cerevisiae SY4 plasma membrane H(+)-ATPase by Fe- and Cu-Fenton reagents was determined in secretory vesicles containing enzyme in which Cys residues were replaced singly or in pairs by Ala. Cys-221 situated in a beta-sheet domain between M2 and M3 segments, phosphorylation domain-located Cys-409 and Cys-532 situated at the ATP-binding site play a role in the inactivation. In the presence of all three residues the enzyme exhibited a certain basic inactivation, which did not change when Cys-532 was replaced with Ala. In mutants having intact Cys-532 but lacking one or both other cysteines, replacement of Cys-221 with Ala led to lower inactivation, suggesting that Cys-221 may serve as a target for metal-catalyzed oxidation and intact Cys-532 promotes this target role of Cys-221. In contrast, the absence of Cys-409 caused higher inactivation by Fe-Fenton. Cys-532 thus seems to serve as a target for Fe-Fenton, intact Cys-409 causing a conformational change that makes Cys-532 less accessible to oxidation. The mutant lacking both Cys-221 and Cys-409 is more sensitive to Fe-Fenton than to Cu-Fenton and the absence of both Cys residues thus seems to expose presumable extra Fe-binding sites. These data and those on protection by ATP, ADP, 1,4-dithiothreitol and deferrioxamine B point to complex interactions between individual parts of the enzyme molecule that determine its sensitivity towards Fenton reagents. ATPase fragmentation caused by the two reagents differed in that the Fe-Fenton reagent produced in Western blot "smears" whereas the Cu-Fenton reagent produced defined fragments.

• MeSH
• Cell Membrane drug effects   enzymology   MeSH
• Cysteine metabolism   MeSH
• Copper MeSH
• Mutation MeSH
• Oxidative Stress drug effects   MeSH
• Hydrogen Peroxide pharmacology   MeSH
• Proton-Translocating ATPases chemistry   genetics   metabolism   MeSH
• Saccharomyces cerevisiae chemistry   drug effects   enzymology   MeSH
• Amino Acid Substitution MeSH
• Free Radicals MeSH
• Structure-Activity Relationship MeSH
• Iron pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cysteine MeSH
• Fenton's reagent MeSH Browser
• Copper MeSH
• Hydrogen Peroxide MeSH
• Proton-Translocating ATPases MeSH
• Free Radicals MeSH
• Iron MeSH

The possible correlation between plasma membrane fluidity changes induced by modified cultivation conditions and cell sensitivity to the killer toxin K1 of Saccharomyces cerevisiae were investigated. Cells grown under standard conditions exhibited high toxin sensitivity. Both a membrane fluidity drop and fluidity rise brought about markedly reduced sensitivity to the toxin. These results do not fit the hypothesis of physiological relevance of direct toxin-lipid interaction, suggesting that the essential event in killer toxin action is interaction with membrane protein(s) that can be negatively influenced by any changes of membrane fluidity.

• MeSH
• Anti-Infective Agents, Local pharmacology   MeSH
• Cell Membrane drug effects   MeSH
• Diphenylhexatriene MeSH
• Ethanol pharmacology   MeSH
• Membrane Fluidity drug effects   MeSH
• Fluorescent Dyes MeSH
• Killer Factors, Yeast MeSH
• Culture Media pharmacology   MeSH
• Mycotoxins pharmacology   MeSH
• Fatty Acids, Unsaturated pharmacology   MeSH
• Saccharomyces cerevisiae drug effects   growth & development   metabolism   MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Infective Agents, Local MeSH
• Diphenylhexatriene MeSH
• Ethanol MeSH
• Fluorescent Dyes MeSH
• K1 killer toxin MeSH Browser
• Killer Factors, Yeast MeSH
• Culture Media MeSH
• Mycotoxins MeSH
• Fatty Acids, Unsaturated MeSH