Showing papers by "John L. Harwood published in 1990"
TL;DR: A cerulenin-insensitive short chain β-ketoacyl-ACP synthetase has been shown to be present in all plant tissues examined and it is highly unlikely that acetyl-CoA:ACP transacylase is rate-limiting for fatty acid synthesis in such tissues.
44 citations
Book•
01 Jan 1990
TL;DR: Fatty acids - structural identification, F.D.Hansen phytochrome and other receptors, L.H.Stobart and S.S.Moore glycolipid analyses and aynthesis in plants, R.J.Horton and J.Williams.
Abstract: Fatty acids - structural identification, F.D.Gunstone triacyglycerol biosynthesis, A.K.Stobart and S.Stymne phospholipids, T.S.Moore glycolipid analyses and aynthesis in plants, R.Douce et al waxes, suberins, and cutins, T.J.Walton polyacetylenes and related compounds, J.Lam and L.Hansen phytochrome and other receptors, L.H.Pratt et al absorption techniques in the study of photosynthesis, P.Mathis chlorophyll flourescence transients, P.Horton and J.R.Bowyer structure and dynamics of plant membranes, P.J.Quinn and W.P.Williams.
37 citations
TL;DR: The results suggest that Sandoz 9785 alters galactolipid metabolism in photosynthetic microalgae but has no great effect on lipid synthesis in non-photosynthetic species.
Abstract: A comparison was made of the effects of the substituted pyridazinone herbicide, 4-chloro-5-(dimethylamino)-2-phenyl 3(2H) pyridazinone (Sandoz 9785; BASF 13-338) on the growth rate and lipid class synthesis of two species of photosynthetic (Chroomanas salina and Nannochloropsis oculata), and one species of non-photosynthetic (Crypthecodinium cohnii), marine microalgae. The growth rate, but not the total lipid content, of all three species was reduced by the herbicide. The percentage distribution of radioactivity incorporated by C. cohnii into lipid classes generally resembled the relative abundance of the classes and the presence of Sandoz 9785 resulted in only small changes in lipid class proportions or in the distribution of radioactivity. In C. salina, the proportion of radioactivity located in monogalactosyldiacylglycerol (MGDG) increased from 9-2% to 20-3%, and that in digalactosyldiacylglycerol (DGDG) from 6-3% to 12-7%, in the presence of the herbicide. In N. oculata the proportion of radioactivity recovered in DGDG, but not MGDG, was increased significantly by the presence of Sandoz 9785. The results suggest that Sandoz 9785 alters galactolipid metabolism in photosynthetic microalgae but has no great effect on lipid synthesis in non-photosynthetic species.
17 citations
TL;DR: Experiments showed clearly that PP600 inhibited de novo fatty acid synthesis at the level of acetyl-CoA carboxylase, suggesting that it may be metabolised to a more active compound in sensitive grass species.
9 citations
TL;DR: The effects of endotoxin on mouse liver phospholipid fatty acid composition have been investigated and increased amounts of oleic acid and palmitic acid were replaced, leading to a reduction in the polyunsaturated to saturated fatty acid ratio.
Abstract: The effects of endotoxin on mouse liver phospholipid fatty acid composition have been investigated. Administration of endotoxin fromSalmonella abortus equi led to a decrease in the polyunsaturated fatty acid content of livers from mice sensitized with Bacille Calmette Guerin (GCG). The content of arachidonic acid fell significantly in both the phosphatidylcholine and phosphatidylinositol fractions whereas in the phosphatidylethanolamine fraction the linoleic acid content was significantly reduced. The polyunsaturated fatty acids were replaced by increased amounts of oleic acid and palmitic acid, leading to a reduction in the polyunsaturated to saturated fatty acid ratio.
7 citations
TL;DR: It is suggested that sterculate inhibits the stearoyl-(acyl-)CoA-dependent pathway but has little effect when phospholipids are used as substrates for acyl chain desaturation.
Abstract: The effect of the cyclopropene fatty acid, sterculic acid, on fatty acid metabolism in the oleaginous yeast Rhodotorula gracilis (CBS 3043) has been studied. Sterculate caused approximately 90% inhibition of [1-14C]sterate desaturation but only about 25% inhibition when [1-14C]acetate was used as precursor. Measurement of acyl-coenzyme A (CoA) pool labelling and the pattern of distribution of radioactivity within lipid classes suggested that the high rate of inhibition of stearate desaturation was due to sterculate reducing the formation of stearoyl-CoA. In agreement with previous suggestions for plant and animal systems, experiments with a post-mitochondrial (20 000 g × 30 min) supernatant suggested that sterculoyl-CoA was the active inhibitor. The action of sterculate on endogenous lipid composition was most marked in stationary-phase cells. In such cells an increase in stearate was seen especially in the triacylglycerol pools, while α-linolenate was increased predominantly in the phospholipid fractions. The increased flux of carbon to α-linolenate at the same time that stearate desaturation appeared to be inhibited by sterculate, indicated that that two separate pathways for desaturation, employing different substrates, may operate in R. gracilis. We suggest that sterculate inhibits the stearoyl-(acyl-)CoA-dependent pathway but has little effect when phospholipids are used as substrates for acyl chain desaturation.
6 citations
01 Jan 1990
3 citations
TL;DR: ~~ ~ 15°C- 30°C shift 2 25.2f 1.3 f 3.3 k 0.7 3 1.2 tr.d.
Abstract: ~~ ~ 15°C- 30°C shift 2 25.2f 1.4 32.2k2.2 tr. 40.3 k 0.3 2.3 f 3.3 n.d. n.d. n.d. 7 20.2 k 0.7 3 1.5 f 3.2 tr. 34.4f0.1 I1.4k 1.2 2.7k3.8 n.d. n.d. 22 15.3k4.9 23.3fl.l 17.8k0.7 26.7f0.2 Y.Yk2.7 7.2f2.4 t r. n.d. 30°C - 15°C shift 2 6.7f 1.3 28.7fO.Y 4.9k 1.5 49.4k5.8 5.8f2.8 3.2f4.5 n.d. n.d. 7 12.lfS.Y 22.0k0.4 11.3kl.3 lY.3k1.5 22.4k2.5 3.6f0.1 3.4k0.8 1.3f1.8 22 5.3k2.9 8.7f4.7 5.7f0.1 21.lf7.1 36.4f0.4 8.9kl.l 8.2f2.2 7.6k2.5
2 citations
01 Jan 1990
1 citations
Book•
01 Jan 1990
TL;DR: Lipid structure and analysis, physical properties of membrane lipids, role of lipids in membranes, fatty acid synthesis, acylthioesterases and acyltransferases, triacylglycerol formation, polar lipid synthesis and transolcation, catabolism oflipids, sterols and terpenoids, modulation of membrane lipid turnover, effect of light and temperature, herbicides and pathological changes in plant lipids.
Abstract: Lipid structure and analysis, physical properties of membrane lipids, role of lipids in membranes, fatty acid synthesis, acylthioesterases and acyltransferases, triacylglycerol formation, polar lipid synthesis and transolcation, catabolism of lipids, sterols and terpenoids, modulation of membrane lipid turnover, effect of light and temperature, herbicides and pathological changes in plant lipids, molecular biology and biotechnology.