scholarly journals Mechanism of cis-trans Isomerization of Unsaturated Fatty Acids in Pseudomonas putida

2003 ◽  
Vol 185 (5) ◽  
pp. 1730-1733 ◽  
Author(s):  
Angelika von Wallbrunn ◽  
Hans Hermann Richnow ◽  
Grit Neumann ◽  
Friedhelm Meinhardt ◽  
Hermann J. Heipieper

ABSTRACT We studied the pattern of the cis-trans isomerization of unsaturated fatty acids in cells of Pseudomonas putida S12 grown in a medium supplemented with oleic acid which was deuterated at both of the C atoms of its double bond. Direct evidence that isomerization does not include a transient saturation of the double bond was obtained. In addition, analysis of the amino acid sequences of the seven known Cti proteins identified them as heme-containing proteins of the cytochrome c type.

2004 ◽  
Vol 66 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Hermann J. Heipieper ◽  
Grit Neumann ◽  
Nadja Kabelitz ◽  
Matthias Kastner ◽  
Hans Hermann Richnow

1966 ◽  
Vol 20 (2) ◽  
pp. 349-362 ◽  
Author(s):  
J. W. Czerkawski ◽  
K. L. Blaxter ◽  
F. W. Wainman

1. Nine experiments, each with one of six sheep with cannulated rumens given a constant diet of dried grass, were made in which oleic, linoleic or linolenic acid was infused into the rumen and energy and lipid metabolism were measured. One experiment was made in which palmitic acid was given. 2. Judged by changes in the composition of isolated fatty acids, the unsaturated fatty acids were hydrogenated in the rumen. An increase in the excretion of lipid in the faeces occurred when the unsaturated acids were given. The heat of combustion of the faeces increased by 12.6±3.0 kcal/100 kcal fatty acid, of which 94% was accounted for by the additional lipid. 3. Methane production fell when the unsaturated fatty acids were infused, the decreases being 13.8±1.6 kcal CH4;/I00 kcal oleic acid, 14.2±1.5 kcal CH4/100 kcal linoIeic acid and 16.4±1.3 kcal CH4/100 kcal Iinolenic acid. The introduction of a double bond into an n-alkyl acid was calculated to reduce methane production by 0.24±0.09 moles/mole double bond. 4. Because the depression of methane production on infusing the fatty acids exceeded the increase in the heat of combustion of the faeces, the metabolizable energy of the fatty acids was 104.1±5.3% of their heat of combustion. 5. The efficiencies with which the fatty acids were used to promote energy retention were 74.6±5.7% for oleic acid, 79.2±2.0 % for linoleic acid and 82.5±3.0% for linolenic acid. These efficiencies agreed with those noted in experiments by others with rats, horses and pigs given glycerides, but were higher than those noted by others when glycerides were added to the diets of ruminants.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Dunfang Wang ◽  
Xuran Ma ◽  
Shanshan Guo ◽  
Yanli Wang ◽  
Tao Li ◽  
...  

As a classic prescription, Huangqin Tang (HQT) has been widely applied to treat ulcerative colitis (UC), although its pharmacological mechanisms are not clear. In this study, urine metabolomics was first analysed to explore the therapeutic mechanisms of HQT in UC rats induced by TNBS. We identified 28 potential biomarkers affected by HQT that might cause changes in urine metabolism in UC rats, mapped the network of metabolic pathways, and revealed how HQT affects metabolism of UC rats. The results showed that UC affects amino acid metabolism and biosynthesis of unsaturated fatty acids and impairs the tricarboxylic acid cycle (TCA cycle). UC induced inflammatory and gastrointestinal reactions by inhibiting the transport of fatty acids and disrupting amino acid metabolism. HQT plays key roles via regulating the level of biomarkers in the metabolism of amino acids, lipids, and so on, normalizing metabolic disorders. In addition, histopathology and other bioinformatics analysis further confirm that HQT altered UC rat physiology and pathology, ultimately affecting metabolic function of UC rats.


1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.


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