scholarly journals Effects of Sterols on the Interaction of SDS, Benzalkonium Chloride, and A Novel Compound, Kor105, with Membranes

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 627 ◽  
Author(s):  
Irene Jiménez-Munguía ◽  
Pavel E. Volynsky ◽  
Oleg V. Batishchev ◽  
Sergey A. Akimov ◽  
Galina A. Korshunova ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Benzalkonium Chloride ◽  
Biological Effects ◽  
Sodium Dodecyl ◽  
Phenyl Group ◽  
Membrane Lipid ◽  
Biophysical Properties ◽  
Membrane Interaction ◽  
Quaternary Nitrogen ◽  
Yeast Strains

Sterols change the biophysical properties of lipid membranes. Here, we analyzed how sterols affect the activity of widely used antimicrobial membrane-active compounds, sodium dodecyl sulfate (SDS) and benzalkonium chloride (BAC). We also tested a novel benzalkonium-like substance, Kor105. Our data suggest that benzalkonium and Kor105 disturb the ordering of the membrane lipid packaging, and this disturbance is dampened by cholesterol. The disturbance induced by Kor105 is stronger than that induced by BAC because of the higher rigidity of the Kor105 molecule due to a shorter linker between the phenyl group and quaternary nitrogen. On the contrary, individual SDS molecules do not cause the disturbance. Thus, in the tested range of concentrations, SDS–membrane interaction is not influenced by cholesterol. To study how sterols influence the biological effects of these chemicals, we used yeast strains lacking Lam1–4 proteins. These proteins transport sterols from the plasma membrane into the endoplasmic reticulum. We found that the mutants are resistant to BAC and Kor105 but hypersensitive to SDS. Together, our findings show that sterols influence the interaction of SDS versus benzalkonium chloride and Kor105 with the membranes in a completely different manner.

Differentiation of Yeast Cultures in Ruminant Feedingstuffs Using a Rapid DNA Fingerprinting Technique

1994 ◽  
Vol 1994 ◽  
pp. 101-101
Author(s):  
Elizabeth Moore ◽  
Denis R. Headon
Keyword(s):  
Sodium Dodecyl ◽  
Yeast Cells ◽  
Microbial Populations ◽  
Yeast Culture ◽  
Yeast Cultures ◽  
Yeast Strains ◽  
Genetic Sequences ◽  
Polymerase Chain ◽  
Different Strains ◽  
Triton X

Research indicates that certain yeast strains are beneficial in their capacity to stimulate key microbial populations. This stimulation is strain specific with similar yeast strains exerting their effect on totally different microbial populations. Future yeast culture supplements may contain mixtures of different strains designed to suit specific diets. This, therefore, requires the development of a rapid sensitive technique to differentiate among taxonomically similar yeast strains in animal diets. This technique, termed the Randomly Amplified Polymorphic DNA (RAPD) assay, is based upon the use of randomly designed short polynucleotide primers to amplify genetic sequences from the DNA of the desired yeast strain. Our objective involves the development of this technique to distinguish between closely related yeast strains present in feed. The feed sample investigated was a standard cattle ration containing three strains of Saccharomyces cerevisiae (1026, 2045 and 2020) and Candida utilis 3001 at a concentration of 106 CFU/g respectively. Isolation of single colonies of yeast strains present was achieved by feed extraction in dilution buffer followed by plating a series of dilutions on rose-bengal agar. Thirty randomly selected colonies were cultured in YPD (1% yeast extract, 2% peptone, 2% glucose) broth for 24 - 30 hours at 30°C. Genomic DNA was isolated from yeast cells by standard methods based on subjection of the cells to vortex mixing in the presence of glass beads, triton X-100, sodium dodecyl sulphate, phenol and chloroform. Isolated DNA from randomly selected colonies was amplified by Polymerase Chain Reaction (PCR) for 45 cycles of 1 min at 94°C, 1 min at 36°C and 1 min at 72°C using randomly designed 10 bp primers.

scholarly journals Genetic Modification of the Salmonella Membrane Physical State Alters the Pattern of Heat Shock Response

2010 ◽  
Vol 192 (7) ◽  
pp. 1988-1998 ◽  
Author(s):  
Amalia Porta ◽  
Zsolt Török ◽  
Ibolya Horvath ◽  
Silvia Franceschelli ◽  
László Vígh ◽  
...  
Keyword(s):  
Heat Shock ◽  
Transcriptional Activation ◽  
Lipid Membranes ◽  
Physical State ◽  
Stress Proteins ◽  
Protein Structures ◽  
Membrane Lipid ◽  
Heat Shock Genes ◽  
Protein Ratio ◽  
Molecular Arrangement

ABSTRACT It is now recognized that membranes are not simple physical barriers but represent a complex and dynamic environment that affects membrane protein structures and their functions. Recent data emphasize the role of membranes in sensing temperature changes, and it has been shown that the physical state of the plasma membrane influences the expression of a variety of genes such as heat shock genes. It has been widely shown that minor alterations in lipid membranes are critically involved in the conversion of signals from the environment to the transcriptional activation of heat shock genes. Previously, we have proposed that the composition, molecular arrangement, and physical state of lipid membranes and their organization have crucial roles in cellular responses during stress caused by physical and chemical factors as well as in pathological states. Here, we show that transformation of Salmonella enterica serovar Typhimurium LT2 (Salmonella Typhimurium) with a heterologous Δ12-desaturase (or with its trans-membrane regions) causes major changes in the pathogen's membrane dynamic. In addition, this pathogen is strongly impaired in the synthesis of major stress proteins (heat shock proteins) under heat shock. These data support the hypothesis that the perception of temperature in Salmonella is strictly controlled by membrane order and by a specific membrane lipid/protein ratio that ultimately causes transcriptional activation of heat shock genes. These results represent a previously unrecognized mode of sensing temperature variation used by this pathogen at the onset of infection.

scholarly journals SugE, a New Member of the SMR Family of Transporters, Contributes to Antimicrobial Resistance inEnterobacter cloacae

2011 ◽  
Vol 55 (8) ◽  
pp. 3954-3957 ◽  
Author(s):  
Gui-Xin He ◽  
Chu Zhang ◽  
Robert R. Crow ◽  
Conner Thorpe ◽  
Huizhong Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Sodium Dodecyl Sulfate ◽  
Benzalkonium Chloride ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Sodium Dodecyl ◽  
Enterobacter Cloacae ◽  
Drug Efflux ◽  
Energy Dependent

ABSTRACTWe cloned a gene,sugE, from the chromosome ofEnterobacter cloacaeATCC 13047. Analysis of the susceptibilities of thesugE-containing strain (Escherichia coliKAM32/pSUGE28) andsugE-deficientE. cloacae(EcΔsugE) showed that SugE confers resistance to cetyltrimethylammonium bromide, cetylpyridinium chloride, tetraphenylphosphonium, benzalkonium chloride, ethidium bromide, and sodium dodecyl sulfate. We also investigated expression ofsugE. We confirm here that SugE fromE. cloacaeis an SMR family transporter as determined by observing its energy-dependent drug efflux activity.

scholarly journals Triple-knockout, synuclein-free mice display compromised lipid pattern

2020 ◽  
Author(s):  
Irina Guschina ◽  
Natalia Ninkina ◽  
Andrei Y. Roman ◽  
Mikhail V. Pokrovskiy ◽  
Vladimir L. Buchman
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Lipid Membranes ◽  
Ether Lipid ◽  
Fatty Acid Analysis ◽  
Membrane Lipid ◽  
Lipid Binding ◽  
Synaptic Functions ◽  
Ethanolamine Plasmalogens ◽  
Lipid Pattern

Abstract Background: Recent studies have implicated synucleins in several reactions during the biosynthesis of lipids and fatty acids in addition to their recognised role in membrane lipid binding and synaptic functions. All members of the synuclein family interact robustly with lipid membranes, and appear to be important for the physiological functions of proteins while influencing the pathological aggregation of α-synuclein. Methods: The following tissues were used for lipid and fatty acid analysis: plasma, liver and two brain areas (cortex and midbrain). Lipid classes were separated using thin-layer chromatography. Fatty acids were analysed using gas chromatography. Results: We describe the importance of long-chain polyunsaturated fatty acids (LCPUFA) and palmitic acid in liver and plasma, reduced triacylglycerol (TAG) accumulation in liver and circulated plasma non-esterified fatty acids in synuclein free mice. In midbrain, observed changes in the relative concentrations of phosphatidylcholine (PC) and cerebrosides (CER) were counterbalanced. In midbrain, we recorded a notable reduction in ethanolamine plasmalogens in synuclein free mice and consider this an important finding considering the abnormal ether lipid metabolism usually associated with neurological disorders.Conclusions: In summary, our data demonstrate that synuclein deficiency can result in alterations of PUFA synthesis, storage lipid accumulation in liver, and reduction of plasmalogens and CER, those polar lipids which are principal compounds of lipid rafts in many tissues. An ablation of all three synuclein family members resulted in more pronounced lipid modifications then previously showed by us γ-synuclein deficiency. Possible mechanisms by which synuclein deficiency may govern the reported modifications of lipid metabolism in TKO mice are proposed and discussed.

scholarly journals The effects of dyslipidaemia and cholesterol modulation on erythrocyte susceptibility to malaria parasite infection

2019 ◽  
Author(s):  
Marion Koch ◽  
Jaimini Cegla ◽  
Ben Jones ◽  
Yuning Lu ◽  
Ziad Mallat ◽  
...  
Keyword(s):  
Serum Cholesterol ◽  
Cholesterol Content ◽  
Membrane Lipid ◽  
Clinical Samples ◽  
Biophysical Properties ◽  
Merozoite Invasion ◽  
Human Red Blood Cells ◽  
Bending Modulus ◽  
Rbc Membrane ◽  
Normal Controls

ABSTRACTMalaria disease commences when blood-stage parasites, called merozoites, invade human red blood cells (RBCs). Whilst the process of invasion is traditionally seen as being entirely merozoite-driven, emerging data suggests RBC biophysical properties markedly influence invasion. Cholesterol is a major determinant of cell membrane biophysical properties. We set out to assess whether cholesterol content in the RBC membrane affects susceptibility to merozoite invasion. Here we demonstrate that RBC bending modulus (a measure of deformability) is markedly affected by artificial modulation of cholesterol content and negatively correlated with merozoite invasion efficiency. Contextualising this observation, we tested a mouse model of hypercholesterolemia and human clinical samples from patients with a range of serum cholesterol concentrations for parasite susceptibility. Hypercholesterolaemia in both human and murine subjects had little effect merozoite invasion efficiency. Furthermore, on testing, RBC cholesterol content in both murine and human hypercholesterolaemia settings was found to be unchanged from normal controls. Serum cholesterol is, therefore, unlikely to impact on RBC susceptibility to merozoite entry. Our work, however, suggests that native polymorphisms that affect RBC membrane lipid composition would be expected to affect parasite entry. This supports investigation of RBC biophysical properties in endemic settings, which may yet identify naturally protective lipid-related polymorphisms.

scholarly journals Asymmetric phospholipids impart novel biophysical properties to lipid bilayers allowing environmental adaptation

2020 ◽  
Author(s):  
Paul Smith ◽  
Dylan M. Owen ◽  
Christian D. Lorenz ◽  
Maria Makarova
Keyword(s):  
Lipid Bilayers ◽  
Mammalian Cells ◽  
Yeast Species ◽  
Membrane Lipid ◽  
Head Group ◽  
Biophysical Properties ◽  
Biophysical Parameters ◽  
Unsaturated Lipids ◽  
Chain Acyl ◽  
Dynamics Simulations

AbstractPhospholipids are a diverse group of biomolecules consisting of a hydrophilic head group and two hydrophobic acyl tails. The nature of the head and length and saturation of the acyl tails are important for defining the biophysical properties of lipid bilayers. It has recently been shown that the membranes of certain yeast species contain high levels of unusual asymmetric phospholipids, consisting of one long and one medium chain acyl moiety – a configuration not common in mammalian cells or other well studied model yeast species. This raises the possibility that structurally asymmetric phospholipids impart novel biophysical properties to the yeast membranes. Here, we use atomistic molecular dynamics simulations (MD) and environmentally-sensitive fluorescent membrane probes to characterize key biophysical parameters of membranes formed from asymmetric lipids for the first time. Interestingly, we show that saturated, but asymmetric phospholipids maintain membrane lipid order across a wider range of temperatures and do not require acyl tail unsaturation or sterols to maintain their properties. This may allow cells to maintain membrane fluidity even in environments which lack the oxygen required for the synthesis of unsaturated lipids and sterols.

The association of intercellular structural glycoproteins with lipids in canine cartilage

1981 ◽  
Vol 59 (3) ◽  
pp. 191-201 ◽  
Author(s):  
Ravi K. Chopra ◽  
J. Michael Bowness
Keyword(s):  
Lipid Membranes ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Matrix Vesicles ◽  
Plasma Lipoproteins ◽  
Connective Tissues ◽  
Density Fraction ◽  
Specific Fraction ◽  
Antigenic Relationships ◽  
Fraction Density

Two noncollagenous insoluble structural glycoprotein fractions (A and G), from uncalcified canine puppy rib cartilage, each contained about 8% of extractable lipid. This percentage of lipid is higher than that found in any of the other tissue fractions obtained by the preparative procedure used. The composition of the lipid extracted from the structural glycoproteins is quite distinct from the lipid in the guanidine∙HCl extract of cartilage, the lipid of cartilage matrix vesicles, and that of other known lipid membranes. On ultracentrifugation, solubilized A or G, obtained by using 50 mM dithiothreitol (DTT) in 5 M guanidine∙HCl followed by dialysis, showed a floating fraction (density 1.14–1.16 g/mL) which was decreased by prior delipidation and increased by lipidation. Chromatography of [3H]palmitate, [14C]cholesterol, or [14C]phosphatidylcholine on Sepharose 2B showed that their elution behaviour is altered in the presence of solubilized A or G. All the labelled lipids cochromatograph, but only with A or G protein in the high molecular weight region. After boiling the low density ultracentrifugation fraction with 1% sodium dodecyl sulfate (SDS), 8 M urea, and 50 mM DTT, disc gel electrophoresis showed that it contained the same subunits as the high density fraction. It is concluded that lipids can readily form a complex with a specific fraction of A or G. This fraction may be a combination of several undissociated subunits or an undenatured form of the proteins. The complex is stable enough to be of possible significance in the metabolism of connective tissues. No antigenic relationships have been found between the cartilage structural glycoproteins or cartilage extracts and the plasma lipoproteins LDL, VLDL, and Lp(a).

scholarly journals Quantitative Analysis of Cold Stress Inducing Lipidomic Changes in Shewanella putrefaciens Using UHPLC-ESI-MS/MS

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4609 ◽  
Author(s):  
Xin Gao ◽  
Wenru Liu ◽  
Jun Mei ◽  
Jing Xie
Keyword(s):  
Cold Stress ◽  
Molecular Species ◽  
Lipid Membranes ◽  
Membrane Integrity ◽  
Shewanella Putrefaciens ◽  
Membrane Lipid ◽  
Cold Adapted ◽  
Esi Ms ◽  
Lipid Molecular Species ◽  
Membrane Lipid Bilayer

Shewanella putrefaciens is a well-known specific spoilage organism (SSO) and cold-tolerant microorganism in refrigerated fresh marine fish. Cold-adapted mechanism includes increased fluidity of lipid membranes by the ability to finely adjust lipids composition. In the present study, the lipid profile of S. putrefaciens cultivated at 30, 20, 10, 4, and 0 °C was explored using ultra-high-pressure liquid chromatography/electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) to discuss the effect of lipid composition on cold-adapted tolerance. Lipidomic analysis detected a total of 27 lipid classes and 606 lipid molecular species in S. putrefaciens cultivated at 30, 20, 10, 4, and 0 °C. S. putrefaciens cultivated at 30 °C (SP-30) had significantly higher content of glycerolipids, sphingolipids, saccharolipids, and fatty acids compared with that at 0 °C (SP-0); however, the lower content of phospholipids (13.97%) was also found in SP-30. PE (30:0), PE (15:0/15:0), PE (31:0), PA (33:1), PE (32:1), PE (33:1), PE (25:0), PC (22:0), PE (29:0), PE (34:1), dMePE (15:0/16:1), PE (31:1), dMePE (15:1/15:0), PG (34:2), and PC (11:0/11:0) were identified as the most abundant lipid molecular species in S. putrefaciens cultivated at 30, 20, 10, 4, and 0 °C. The increase of PG content contributes to the construction of membrane lipid bilayer and successfully maintains membrane integrity under cold stress. S. putrefaciens cultivated at low temperature significantly increased the total unsaturated liquid contents but decreased the content of saturated liquid contents.

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