Lipid Metabolism as a Site of Herbicide Action

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 477-480 ◽  
Author(s):  
J. B. St. John ◽  
J. L. Hilton
Keyword(s):  
Membrane Lipids ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Cell Membrane Permeability ◽  
Glyceride Synthesis ◽  
Membrane Structure And Function ◽  
And Function ◽  
A Site

Dinoseb (2-sec-butyl-4,6-dinitrophenol) and MBR 8251 [1,1 1-trifluoro-4′-(phenylsulfonyl)-methanesulfono-o-toluidide] inhibited enzymic synthesis of glycerides in vitro. The physiological significance of this inhibition was confirmed in intact wheat [Triticum aestivumL., ‘Mediterranean’ (C.I. 5303)] seedlings; dinoseb and MBR 8251 inhibition of glyceride synthesis in vivo was evidenced by a buildup in free fatty acids and a decrease in neutral and polar lipids. Glyceride synthesis and growth were reduced approximately equally by dinoseb and MBR 8251. However, polar (membrane) lipids were reduced more drastically than growth. It is suggested that dinoseb and MBR 8251 alter membrane structure and function through an inhibition of membrane lipid synthesis. DNP (dinitrophenol) was only slightly inhibitory in either the in vitro or in vivo system. Dinoseb was more effective than MBR 8251 in destruction of cell membrane permeability of intact roots immediately after treatment.

scholarly journals Impact of Membrane Lipids on UapA and AzgA Transporter Subcellular Localization and Activity in Aspergillus nidulans

2021 ◽  
Vol 7 (7) ◽  
pp. 514
Author(s):  
Mariangela Dionysopoulou ◽  
George Diallinas
Keyword(s):  
Plasma Membrane ◽  
Subcellular Localization ◽  
Aspergillus Nidulans ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Lipid Biosynthesis ◽  
Transport Kinetics ◽  
Negative Effect ◽  
And Function

Recent biochemical and biophysical evidence have established that membrane lipids, namely phospholipids, sphingolipids and sterols, are critical for the function of eukaryotic plasma membrane transporters. Here, we study the effect of selected membrane lipid biosynthesis mutations and of the ergosterol-related antifungal itraconazole on the subcellular localization, stability and transport kinetics of two well-studied purine transporters, UapA and AzgA, in Aspergillus nidulans. We show that genetic reduction in biosynthesis of ergosterol, sphingolipids or phosphoinositides arrest A. nidulans growth after germling formation, but solely blocks in early steps of ergosterol (Erg11) or sphingolipid (BasA) synthesis have a negative effect on plasma membrane (PM) localization and stability of transporters before growth arrest. Surprisingly, the fraction of UapA or AzgA that reaches the PM in lipid biosynthesis mutants is shown to conserve normal apparent transport kinetics. We further show that turnover of UapA, which is the transporter mostly sensitive to membrane lipid content modification, occurs during its trafficking and by enhanced endocytosis, and is partly dependent on autophagy and Hect-type HulARsp5 ubiquitination. Our results point out that the role of specific membrane lipids on transporter biogenesis and function in vivo is complex, combinatorial and transporter-dependent.

Study of the Protective Effect of Schizandra chinensis Polysaccharide on Oxidative Damage of Mouse Spermatozoa In Vitro

2014 ◽  
Vol 912-914 ◽  
pp. 1973-1977
Author(s):  
Dong Hai Zhao ◽  
Yan Zhang ◽  
Zhen Yuan ◽  
Meng Lu Li ◽  
Wei Yun Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protective Effect ◽  
Damage Model ◽  
Membrane Lipid ◽  
Control Group ◽  
Stress Injury ◽  
Membrane Structure And Function ◽  
Stress Damage ◽  
And Function

The aim of the study: This study was conducted to evaluate oxidative stress damage model caused by reactive oxygen species production was prepared by heating injury and protective effect of SCP on spermatozoa membrane structure and function in vitro. Materials and methods: mouse eupyrene sperm suspensions were prepared and were randomly divided into six groups. The control group was maintained with PBS. The positive medicine group was received PBS contained vitamin E (0.25 mg /ml) .The SCP group was then given SCP (0.2, 0.4 and 0.8 mg /ml) respectively. All the groups except control group were treated with using heat stress injury. Degree of injury of spermatozoa membrane lipid peroxidation was detected. Results: The vitality of total superoxide dismutase (T-SOD) was increased and the quality of malondialdehyde (MDA) was decreased in different degree with each concentration of SCP. The protective effect of 0.4 mg /ml and 0.8 mg /ml SCP on spermatozoa membrane was obviously surpass to positive medicine group. These findings indicate that SCP could be potentially useful for the treatment of oxidative stress damage in spermatozoa.

scholarly journals Modulation Effects of Curcumin on Erythrocyte Ion-Transporter Activity

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Prabhakar Singh ◽  
Syed Ibrahim Rizvi
Keyword(s):  
Oxidative Stress ◽  
Membrane Lipids ◽  
Curcuma Longa ◽  
Membrane Lipid ◽  
Membrane Transporters ◽  
Protective Mechanism ◽  
Lipid Hydroperoxides ◽  
Beneficial Effects

Curcumin ((1E,6E)-1,7-Bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), the yellow biphenolic pigment isolated from turmeric (Curcuma longa), has various medicinal benefits through antioxidation, anti-inflammation, cardiovascular protection, immunomodulation, enhancing of the apoptotic process, and antiangiogenic property. We explored the effects of curcuminin vitro(10−5 M to 10−8 M) andin vivo(340 and 170 mg/kg b.w., oral) on Na+/K+ATPase (NKA), Na+/H+exchanger (NHE) activity, and membrane lipid hydroperoxides (ROOH) in control and experimental oxidative stress erythrocytes of Wistar rats. As a result, we found that curcumin potently modulated the membrane transporters activity with protecting membrane lipids against hydro-peroxidation in control as well as oxidatively challenged erythrocytes evidenced by stimulation of NKA, downregulation of NHE, and reduction of ROOH in the membrane. The observed results corroborate membrane transporters activity with susceptibility of erythrocyte membrane towards oxidative damage. Results explain the protective mechanism of curcumin against oxidative stress mediated impairment in ions-transporters activity and health beneficial effects.

scholarly journals Effect of hyperphenylalaninaemia on lipid synthesis from ketone bodies by rat brain

1976 ◽  
Vol 154 (2) ◽  
pp. 319-325 ◽  
Author(s):  
M S. Patel ◽  
O E. Owen
Keyword(s):  
Rat Brain ◽  
Ketone Bodies ◽  
Brain Slices ◽  
Lipid Synthesis ◽  
Coa Transferase ◽  
Old Rats ◽  
And Function ◽  
Developing Rat

The effect of hyperphenylalaninaemia on the metabolism of ketone bodies in vivo and in vitro by developing rat brain was investigated. The incorporation in vivo of [14C]acetoacetate into cerebral lipids was decreased by both chronic (for 3 days) and acute (for 6h) hyperphenylalaninaemia induced by injecting phenylalanine into 1-week-old rats. In studies in vitro it was observed that the incorporation of the radioactivity from [14C]acetoacetate and 3-hydroxy[14C]butyrate into cerebral lipids was inhibited by phenyl-pyruvate, but not by phenylalanine. Phenylpyruvate also inhibited the incorporation of 3H from 3H2O into lipids by brain slices metabolizing either 3-hydroxybutyrate or acetoacetate in the presence of glucose. These findings suggest that the decrease in the incorporation in vivo of [14C]acetoacetate into cerebral lipids in hyperphenylalaninaemic rats is most likely caused by phenylpyruvate and not by phenylalanine. Phenylpyruvate as well as phenylalanine had no inhibitory effects on ketone-body-catabolizing enzymes, namely 3-hydroxybutyrate dehydrogenase, 3-oxo acid CoA-transferase and acetoacetyl-CoA thiolase, in rat brain. Phenylpyruvate but not phenylalanine inhibited the activity of the 2-oxoglutarate dehydrogenase complex from rat and human brain. These findings suggest that the metabolism of ketone bodies is impaired in brains of untreated phenylketonuric patients, and in turn may contribute to the diminution of mental development and function associated with phenylketonuria.

scholarly journals Lipids in Pathophysiology and Development of the Membrane Lipid Therapy: New Bioactive Lipids

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 919
Author(s):  
Manuel Torres ◽  
Sebastià Parets ◽  
Javier Fernández-Díaz ◽  
Roberto Beteta-Göbel ◽  
Raquel Rodríguez-Lorca ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Lipid Composition ◽  
Membrane Lipids ◽  
Therapeutic Potential ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Bioactive Lipids ◽  
Membrane Lipid Composition ◽  
Membrane Structure And Function ◽  
And Function

Membranes are mainly composed of a lipid bilayer and proteins, constituting a checkpoint for the entry and passage of signals and other molecules. Their composition can be modulated by diet, pathophysiological processes, and nutritional/pharmaceutical interventions. In addition to their use as an energy source, lipids have important structural and functional roles, e.g., fatty acyl moieties in phospholipids have distinct impacts on human health depending on their saturation, carbon length, and isometry. These and other membrane lipids have quite specific effects on the lipid bilayer structure, which regulates the interaction with signaling proteins. Alterations to lipids have been associated with important diseases, and, consequently, normalization of these alterations or regulatory interventions that control membrane lipid composition have therapeutic potential. This approach, termed membrane lipid therapy or membrane lipid replacement, has emerged as a novel technology platform for nutraceutical interventions and drug discovery. Several clinical trials and therapeutic products have validated this technology based on the understanding of membrane structure and function. The present review analyzes the molecular basis of this innovative approach, describing how membrane lipid composition and structure affects protein-lipid interactions, cell signaling, disease, and therapy (e.g., fatigue and cardiovascular, neurodegenerative, tumor, infectious diseases).

scholarly journals Membrane Interactivity of Non-steroidal Anti-inflammatory Drugs: A Literature Review

2020 ◽  
pp. 1-30
Author(s):  
Hironori Tsuchiya ◽  
Maki Mizogami
Keyword(s):  
Membrane Fluidity ◽  
Membrane Lipids ◽  
Direct Interaction ◽  
Membrane Lipid ◽  
Lipid Phase ◽  
Lipid Bilayer Membranes ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Background: Although the mode of action of non-steroidal anti-inflammatory drugs (NSAIDs) has been exclusively referred to as inhibition of cyclooxygenase, their broad pharmacological and toxicological spectra are not necessarily interpreted by the direct interaction with such enzyme proteins. Aims: Since NSAIDs have the common amphiphilic structure, they have the possibility of acting on membrane-constituting lipids. In order to gain insights into the additional mechanism of NSAIDs, we reviewed their membrane interactivity to modify the physicochemical properties of membranes. Methodology: We retrieved scientific articles from PubMed/MEDLINE, Google Scholar and ACS Publications by searching databases from 1990 to 2019. Research papers published in English in the internationally recognized journals and on-line journals were cited with preference to more recent publications. Collected articles were reviewed by title, abstract and text for relevance. Results: Results of the literature search indicated that NSAIDs structure-specifically cause the in vitro and in vivo interactions with artificial and biological membranes to change membrane fluidity, lipid phase transition and permeability. The features and potencies of their membrane interactivity vary depending on drug concentration, medium pH and membrane lipid composition. In addition to membrane proteins, NSAIDs act on membrane lipids to exhibit the anti-inflammatory and anti-tumor activity by interacting with lipid bilayer membranes at relatively low concentrations to decrease membrane fluidity and thereby affect the enzymatic activity of membrane-associated proteins and to exhibit the gastrointestinal and cardiovascular toxicity by interacting with membranous phospholipids at relatively high concentrations to increase membrane fluidity and thereby impair the membrane-relevant biofunctions. Other diverse effects of NSAIDs may also be related to their membrane interactions. Conclusion: NSAIDs share the membrane interactivity common to them as one of possible pharmacological and toxicological mechanisms.            

scholarly journals In Vitro Resistance of Staphylococcus aureus to Thrombin-Induced Platelet Microbicidal Protein Is Associated with Alterations in Cytoplasmic Membrane Fluidity

2000 ◽  
Vol 68 (6) ◽  
pp. 3548-3553 ◽  
Author(s):  
Arnold S. Bayer ◽  
Rajendra Prasad ◽  
Jyotsna Chandra ◽  
Anjni Koul ◽  
M. Smriti ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Membrane ◽  
Membrane Fluidity ◽  
Cytoplasmic Membrane ◽  
Membrane Lipids ◽  
Serial Passage ◽  
Membrane Structure And Function ◽  
Platelet Microbicidal Protein ◽  
And Function

ABSTRACT Platelet microbicidal proteins (PMPs) are small, cationic peptides which possess potent microbicidal activities against common bloodstream pathogens, such as Staphylococcus aureus. We previously showed that S. aureus strains exhibiting resistance to thrombin-induced PMP (tPMP-1) in vitro have an enhanced capacity to cause human and experimental endocarditis (T. Wu, M. R. Yeaman, and A. S. Bayer, Antimicrob. Agents Chemother. 38:729–732, 1994; A. S. Bayer et al., Antimicrob. Agents Chemother. 42:3169–3172, 1998; V. K. Dhawan et al., Infect. Immun. 65:3293–3299, 1997). However, the mechanisms mediating tPMP-1 resistance in S. aureus are not fully delineated. The S. aureus cell membrane appears to be a principal target for the action of tPMP-1. To gain insight into the basis of tPMP-1 resistance, we compared several parameters of membrane structure and function in three tPMP-1-resistant (tPMP-1r) strains and their genetically related, tPMP-1-susceptible (tPMP-1s) counterpart strains. The tPMP-1rstrains were derived by three distinct methods: transposon mutagenesis, serial passage in the presence of tPMP-1 in vitro, or carriage of a naturally occurring multiresistance plasmid (pSK1). All tPMP-1r strains were found to possess elevated levels of longer-chain, unsaturated membrane lipids, in comparison to their tPMP-1s counterparts. This was reflected in corresponding differences in cell membrane fluidity in the strain pairs, with tPMP-1r strains exhibiting significantly higher degrees of fluidity as assessed by fluorescence polarization. These data provide further support for the concept that specific alterations in the cytoplasmic membrane of S. aureus strains are associated with tPMP-1 resistance in vitro.

scholarly journals In Vivo Assay Reveals Microbial OleA Thiolases Initiating Hydrocarbon and β-Lactone Biosynthesis

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Megan D. Smith ◽  
Serina L. Robinson ◽  
Mandkhai Molomjamts ◽  
Lawrence P. Wackett
Keyword(s):  
Metabolic Pathways ◽  
Xanthomonas Campestris ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Limited Information ◽  
Content Type ◽  
Bacterial Phyla ◽  
Long Chain

ABSTRACT OleA, a member of the thiolase superfamily, is known to catalyze the Claisen condensation of long-chain acyl coenzyme A (acyl-CoA) substrates, initiating metabolic pathways in bacteria for the production of membrane lipids and β-lactone natural products. OleA homologs are found in diverse bacterial phyla, but to date, only one homodimeric OleA has been successfully purified to homogeneity and characterized in vitro. A major impediment for the identification of new OleA enzymes has been protein instability and time-consuming in vitro assays. Here, we developed a bioinformatic pipeline to identify OleA homologs and a new rapid assay to screen OleA enzyme activity in vivo and map their taxonomic diversity. The screen is based on the discovery that OleA displayed surprisingly high rates of p-nitrophenyl ester hydrolysis, an activity not shared by other thiolases, including FabH. The high rates allowed activity to be determined in vitro and with heterologously expressed OleA in vivo via the release of the yellow p-nitrophenol product. Seventy-four putative oleA genes identified in the genomes of diverse bacteria were heterologously expressed in Escherichia coli, and 25 showed activity with p-nitrophenyl esters. The OleA proteins tested were encoded in variable genomic contexts from seven different phyla and are predicted to function in distinct membrane lipid and β-lactone natural product metabolic pathways. This study highlights the diversity of unstudied OleA proteins and presents a rapid method for their identification and characterization. IMPORTANCE Microbially produced β-lactones are found in antibiotic, antitumor, and antiobesity drugs. Long-chain olefinic membrane hydrocarbons have potential utility as fuels and specialty chemicals. The metabolic pathway to both end products share bacterial enzymes denoted as OleA, OleC, and OleD that transform acyl-CoA cellular intermediates into β-lactones. Bacteria producing membrane hydrocarbons via the Ole pathway additionally express a β-lactone decarboxylase, OleB. Both β-lactone and olefin biosynthesis pathways are initiated by OleA enzymes that define the overall structure of the final product. There is currently very limited information on OleA enzymes apart from the single representative from Xanthomonas campestris. In this study, bioinformatic analysis identified hundreds of new, putative OleA proteins, 74 proteins were screened via a rapid whole-cell method, leading to the identification of 25 stably expressed OleA proteins representing seven bacteria phyla.

scholarly journals Self-assembly of spectrin oligomers in vitro: a basis for a dynamic cytoskeleton.

1981 ◽  
Vol 88 (2) ◽  
pp. 463-468 ◽  
Author(s):  
J S Morrow ◽  
V T Marchesi
Keyword(s):  
Self Assembly ◽  
Erythrocyte Membranes ◽  
Membrane Structure And Function ◽  
High Concentrations ◽  
The Stability ◽  
And Function ◽  
Low Ionic Strength ◽  
Affinity Interaction

Purified human erythrocyte spectrin is able to form large oligomeric species without the collaboration of any other proteins. This reversible self-assembly process is both temperature and concentration dependent and seems to be mediated by the same kinds of low affinity noncovalent associations between spectrin monomers that promote tetramer formation. Low ionic strength extracts of erythrocyte membranes also contain these oligomeric species. These results support the idea that spectrin oligomers and the factors that regulate their formation may be responsible for both the stability and the versatility of the erythrocyte membrane cytoskeleton. It is postulated that the high concentrations of spectrin necessary for oligomerization are maintained in vivo by a high-affinity interaction with ankyrin. Such a coupling of high and low affinity interactions in multifunctional proteins may have significant implications for membrane structure and function.

Lipid synthesis by the monoglyceride and α-glycerophosphate pathways in sheep intestine

1969 ◽  
Vol 47 (11) ◽  
pp. 1013-1020 ◽  
Author(s):  
H. M. Cunningham ◽  
W. M. F. Leat
Keyword(s):  
Palmitic Acid ◽  
Lipid Synthesis ◽  
Adult Rats ◽  
Adult Sheep ◽  
Glyceride Synthesis ◽  
Intestinal Segments ◽  
Hydrolysis Of

Double-labelled monopalmitin containing 14C-glycerol and 3H-palmitic acid was used in vitro in intestinal segments and in vivo in intestinal loops of sheep to determine if triglycerides could be synthesized by both the monoglyceride and α-glycerophosphate pathways. Total glyceride synthesis in vitro by the combined pathways was highest in 87- and 120-day foetal lambs, followed in declining order by 6- to 13-day lambs, adult sheep, and adult rats (used for comparative purposes). The minimum percentage of the glycerides synthesized by the monoglyceride pathway using 1-monopalmitin as a precursor was: foetus 20, lamb 29, adult sheep 28, and rat 45. These are minimum values because appreciable hydrolysis of 1-monopalmitin occurred during incubation: 61% in rats, 68% in lambs, 71% in adult sheep, and 80% in foetal sheep. 2-Monopalmitin was more resistant to hydrolysis by intestinal segments and loops and resulted in at least 43% synthesis of glycerides by the monoglyceride pathway in segments of adult sheep intestine, compared to 26% with 1-monopalmitin.

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