scholarly journals Action of long-chain fatty acids in vitro on Ca2+-stimulatable, Mg2+-dependent ATPase activity in human red cell membranes

1987 ◽  
Vol 248 (2) ◽  
pp. 511-516 ◽  
Author(s):  
F B Davis ◽  
P J Davis ◽  
S D Blas ◽  
M Schoenl
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Oleic Acid ◽  
Thyroid Hormone ◽  
Atpase Activity ◽  
Red Cell ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Human red cell membrane Ca2+-stimulatable, Mg2+-dependent adenosine triphosphatase (Ca2+-ATPase) activity and its response to thyroid hormone have been studied following exposure of membranes in vitro to specific long-chain fatty acids. Basal enzyme activity (no added thyroid hormone) was significantly decreased by additions of 10(-9)-10(-4) M-stearic (18:0) and oleic (18:1 cis-9) acids. Methyl oleate and elaidic (18:1 trans-9), palmitic (16:0) and lauric (12:0) acids at 10(-6) and 10(-4) M were not inhibitory, nor were arachidonic (20:4) and linolenic (18:3) acids. Myristic acid (14:0) was inhibitory only at 10(-4) M. Thus, chain length of 18 carbon atoms and anionic charge were the principal determinants of inhibitory activity. Introduction of a cis-9 double bond (oleic acid) did not alter the inhibitory activity of the 18-carbon moiety (stearic acid), but the trans-9 elaidic acid did not cause enzyme inhibition. While the predominant effect of fatty acids on erythrocyte Ca2+-ATPase in situ is inhibition of basal activity, elaidic, linoleic (18:2) and palmitoleic (16:1) acids at 10(-6) and 10(-4) M stimulated the enzyme. Methyl elaidate was not stimulatory. These structure-activity relationships differ from those described for fatty acids and purified red cell Ca2+-ATPase reconstituted in liposomes. Thyroid hormone stimulation of Ca2+-ATPase was significantly decreased by stearic and oleic acids (10(-9)-10(-4) M), but also by elaidic, linoleic, palmitoleic and myristic acids. Arachidonic, palmitic and lauric acids were ineffective, as were the methyl esters of oleic and elaidic acids. Thus, inhibition of the iodothyronine effect on Ca2+-ATPase by fatty acids has similar, but not identical, structure-activity relationships to those for basal enzyme activity. To examine mechanisms for these fatty acid effects, we studied the action of oleic and stearic acids on responsiveness of the enzyme to purified calmodulin, the Ca2+-binding activator protein for Ca2+-ATPase. Oleic and stearic acids (10(-9)-10(-4) M) progressively inhibited, but did not abolish, enzyme stimulation by calmodulin (10(-9) M). Double-reciprocal analysis of the effect of oleic acid on calmodulin stimulation indicated noncompetitive inhibition. Addition of calmodulin to membranes in the presence of equimolar oleic acid restored basal enzyme activity. Oleic acid also reduced 125I-calmodulin binding to membranes, but had no effect on the binding of [125I]T4 by ghosts. The mechanism of the decrease by long chain fatty acids of Ca2+-ATPase activity in situ in human red cell ghosts thus is calmodulin-dependent and involves reduction in membrane binding of calmodulin.

scholarly journals Rumen Fermentation In Vitro as Influenced by Long Chain Fatty Acids

1984 ◽  
Vol 67 (7) ◽  
pp. 1439-1444 ◽  
Author(s):  
William Chalupa ◽  
Bonnie Rickabaugh ◽  
D. Kronfeld ◽  
S. David Sklan
Keyword(s):  
Fatty Acids ◽  
Rumen Fermentation ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Chloroacetamide Mode of Action, I: Inhibition of Very Long Chain Fatty Acid Synthesis in Scenedesmus acutus

1998 ◽  
Vol 53 (11-12) ◽  
pp. 995-1003 ◽  
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Synthesis ◽  
Resistant Cell Line ◽  
Long Chain Fatty Acids ◽  
Scenedesmus Acutus ◽  
Long Chain ◽  
Chain Fatty Acids

Abstract Herbicidal chloroacetamides cause a very sensitive inhibition of fatty acid incorporation into an insoluble cell wall fraction of Scenedesmus acutus. The molecular basis was investigated in more detail. After incubation of the algae with [14C]oleic acid and saponification, the remaining pellet was solubilized and fractionated consecutively with chloroform / methanol, phosphate buffer, amylase, pronase, and finally with dioxane/HCl. By acid hydrolysis in dioxane a part of the cell wall residue was solubilized showing inhibition of exogenously applied oleic acid and other labelled precursors such as stearic acid, palmitic acid, and acetate. After extraction of this dioxane-soluble subfraction with hexane, HPLC could separate labelled metabolites less polar than oleic acid. T heir formation was completely inhibited by chloroacetam ides, e.g. 1 μᴍ metazachlor. This effect was also observed with the herbicidally active 5-enantiomer of metolachlor while the inactive R-enantiomer had no influence. These strongly inhibited metabolites could be characterized by radio-HPLC /MS as very long chain fatty acids (VLCFAs) with a carbon chain between 20 and 26. Incubating am etazachlor-resistant cell line of S. acutus (Mz-1) with [14C]oleic acid, V LCFA s could not be detected in the dioxane/ HCl-subfraction. Furthermore, comparing the presence of endogenous fatty acids in wildtype and mutant Mz-1 the VLCFA content of the mutant is very low, while the content of long chain fatty acids (C16 -18) is increased, particularly oleic acid. Obviously, the phytotoxicity of chloroacetam ides in S. acutus is due to inhibition of VLCFA synthesis. The resistance of the mutant to metazachlor has a bearing on the higher amount of long chain fatty acids replacing the missing VLCFAs in essential membranes or cell wall components.

scholarly journals The Multifunctional β-Oxidation Enzyme Is Required for Full Symptom Development by the Biotrophic Maize Pathogen Ustilago maydis

2006 ◽  
Vol 5 (12) ◽  
pp. 2047-2061 ◽  
Author(s):  
Jana Klose ◽  
James W. Kronstad
Keyword(s):  
Fatty Acids ◽  
Ustilago Maydis ◽  
Long Chain Fatty Acids ◽  
In Planta ◽  
Gene Encoding ◽  
Metabolic Role ◽  
Fungal Phytopathogen ◽  
Long Chain ◽  
Chain Fatty Acids

ABSTRACT The transition from yeast-like to filamentous growth in the biotrophic fungal phytopathogen Ustilago maydis is a crucial event for pathogenesis. Previously, we showed that fatty acids induce filamentation in U. maydis and that the resulting hyphal cells resemble the infectious filaments observed in planta. To explore the potential metabolic role of lipids in the morphological transition and in pathogenic development in host tissue, we deleted the mfe2 gene encoding the multifunctional enzyme that catalyzes the second and third reactions in β-oxidation of fatty acids in peroxisomes. The growth of the strains defective in mfe2 was attenuated on long-chain fatty acids and abolished on very-long-chain fatty acids. The mfe2 gene was not generally required for the production of filaments during mating in vitro, but loss of the gene blocked extensive proliferation of fungal filaments in planta. Consistent with this observation, mfe2 mutants exhibited significantly reduced virulence in that only 27% of infected seedlings produced tumors compared to 88% tumor production upon infection by wild-type strains. Similarly, a defect in virulence was observed in developing ears upon infection of mature maize plants. Specifically, the absence of the mfe2 gene delayed the development of teliospores within mature tumor tissue. Overall, these results indicate that the ability to utilize host lipids contributes to the pathogenic development of U. maydis.

THE BIOSYNTHESIS OF LONG-CHAIN FATTY ACIDS IN THE DEVELOPING CASTOR BEAN

1965 ◽  
Vol 43 (1) ◽  
pp. 49-62 ◽  
Author(s):  
D. T. Canvin
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Ricinoleic Acid ◽  
Castor Bean ◽  
Diethyl Malonate ◽  
Water Soluble ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Acetate-1-C14 and acetate-2-C14 were supplied to slices of developing castor bean endosperm. The molecules were extensively incorporated into long-chain fatty acids, water-soluble compounds, and protein. Oleic acid was the fatty acid initially labelled from acetate and it was the precursor of ricinoleic acid. Aerobic conditions were required for the formation of oleic acid and for the conversion of oleic acid to ricinoleic acid. Under anaerobic conditions the incorporation of acetate carbon into fatty acids was inhibited more than 90% and almost all of the C14 was found in stearic and palmitic acids. Stearic acid appeared to be formed first and palmitic acid appeared to be derived from it through a shortening of the chain. The position of linoleic acid in the fatty acid interconversions was not clear except that it was not a free intermediate in the conversion of oleic acid to ricinoleic acid.Malonate-C14 was only absorbed slightly by the tissue and although absorption could be increased by the use of diethyl malonate the metabolism of the compound was not facilitated. Because of its poor utilization by the tissue the role of malonate in long-chain fatty acid synthesis in this tissue could not be ascertained.

Synthesis in vitro of very long chain fatty acids in Vibrio sp. strain ABE-1

1992 ◽  
Vol 157 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Naoki Morita ◽  
Nobuhiro Okajima ◽  
Masaru Gotoh ◽  
Hideyuki Hayashi ◽  
Hidetoshi Okuyama ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

The effects of fatty acids on pure cultures of rumen bacteria

1973 ◽  
Vol 81 (1) ◽  
pp. 107-112 ◽  
Author(s):  
C. Henderson
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Rumen Bacteria ◽  
Long Chain Fatty Acids ◽  
Selenomonas Ruminantium ◽  
Low Concentrations ◽  
Pure Cultures ◽  
Long Chain ◽  
Chain Fatty Acids

SummaryThe effects of fatty acids, at low concentrations (0–005-O5 g/1), on the growth of seven species of rumen bacteria were examined.Anaerovibrio lipolytica(strain 5 S),Peptostreptococcus elsdenii(type 2),Bacteroides ruminicola46/52 andSelenomonas ruminantium(strain 17) were unaffected by addition of oleic acid to the medium. Growth ofButyrivibrioB 835 was stimulated by low concentrations of oleic (< 0–01 g/1), lauric (< 0–1 g/1) or capric (< 0–1 g/1) acids while higher concentrations of these acids were inhibitory. Myristic, palmitic and stearic acids were inhibitory at all concentrations tested.Ruminococcus4263/1 was inhibited at all concentrations of the six acids. Production of methane by pure cultures ofMethanobacterium ruminantiumwas also inhibited by the additions of long-chain fatty acids. Oleic acid was the most inhibitory of the series of acids. These results are consistent with the reported effects of lipids on rumen function.

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