Flip-Flop Is Slow and Rate Limiting for the Movement of Long Chain Anthroyloxy Fatty Acids across Lipid Vesicles†

Biochemistry ◽  
1997 ◽  
Vol 36 (19) ◽  
pp. 5702-5711 ◽  
Author(s):  
Alan M. Kleinfeld ◽  
Peter Chu ◽  
Judith Storch
Keyword(s):  
Fatty Acids ◽  
Lipid Vesicles ◽  
Flip Flop ◽  
Rate Limiting ◽  
Long Chain

Changes of Intrinsic Membrane Potentials Induced by Flip-Flop of Long-Chain Fatty Acids†

Biochemistry ◽  
2000 ◽  
Vol 39 (7) ◽  
pp. 1834-1839 ◽  
Author(s):  
Elena E. Pohl ◽  
Uwe Peterson ◽  
Jan Sun ◽  
Peter Pohl
Keyword(s):  
Fatty Acids ◽  
Membrane Potentials ◽  
Long Chain Fatty Acids ◽  
Flip Flop ◽  
Long Chain ◽  
Chain Fatty Acids

Anaerobic batch degradation of solid poultry slaughterhouse waste

2000 ◽  
Vol 41 (3) ◽  
pp. 33-41 ◽  
Author(s):  
E. Salminen ◽  
J. Rintala ◽  
L.Ya. Lokshina ◽  
V.A. Vavilin
Keyword(s):  
Fatty Acids ◽  
Methane Production ◽  
Long Chain Fatty Acids ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Propionate Degradation ◽  
Waste Degradation ◽  
New Generation ◽  
Rate Limiting ◽  
Long Chain

We studied anaerobic batch degradation of solid poultry slaughterhouse wastes with different initial waste and inoculum concentrations and waste-to-inoculum ratios and simulated the dynamics of the process with a new generation <METHANE> model. Our modelling results suggest that inhibited propionate degradation by long-chain fatty acids (LCFA) and inhibited hydrolysis by a high propionate concentration constituted the rate-limiting step in the waste degradation. Palmitate was the most abundant LCFA in the assays. Within 27 days of incubation, up to 0.55 to 0.67 m3 of methane (STP)/kg VS added was produced under the studied conditions. Lower waste-to-inoculum ratios exhibited a faster onset and rate of specific methane production. In all the assays, ammonification occurred within 3 to 6 days and accounted for 50 to 60% of total nitrogen.

The surprising diversity of Δ6-desaturase substrates

2004 ◽  
Vol 32 (1) ◽  
pp. 86-87 ◽  
Author(s):  
H. Guillou ◽  
S. D'Andrea ◽  
V. Rioux ◽  
S. Jan ◽  
P. Legrand
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Single Gene ◽  
Mammalian Species ◽  
Hexadecenoic Acid ◽  
Gene Encoding ◽  
Rate Limiting ◽  
Long Chain ◽  
Δ6 Desaturase

A single gene encoding a δ6-desaturase (FADS2) has been isolated and characterized in mammalian species. This δ6-desaturase plays a major role in the biosynthesis of PUFAs (polyunsaturated fatty acids). It catalyses the rate-limiting desaturation of linoleic acid (C18:2n−6) and α-linolenic acid (C18:3n−3) required for the biosynthesis of long-chain PUFAs. Moreover, recent studies have provided strong evidence that this δ6-desaturase also acts on 24-carbon PUFAs of both the n−6 and n−3 series. Another substrate of this δ6-desaturase has been identified through complementary works from different investigators. This δ6-desaturase acts on a saturated fatty acid, palmitic acid (C16:0), leading to the newly characterized biosynthesis of hexadecenoic acid (C16:1n−10) or sapienate.

Biophysics (and sociology) of ceramides.

2005 ◽  
Vol 72 ◽  
pp. 177-188 ◽  
Author(s):  
Félix M. Goñi ◽  
F-Xabier Contreras ◽  
L-Ruth Montes ◽  
Jesús Sot ◽  
Alicia Alonso
Keyword(s):  
Cell Biology ◽  
Positive Curvature ◽  
Acyl Chain ◽  
Cell Signalling ◽  
Hexagonal Structure ◽  
Lipid Monolayer ◽  
Flip Flop ◽  
Long Chain ◽  
Bilayer Permeability

In the past decade, the long-neglected ceramides (N-acylsphingosines) have become one of the most attractive lipid molecules in molecular cell biology, because of their involvement in essential structures (stratum corneum) and processes (cell signalling). Most natural ceramides have a long (16-24 C atoms) N-acyl chain, but short N-acyl chain ceramides (two to six C atoms) also exist in Nature, apart from being extensively used in experimentation, because they can be dispersed easily in water. Long-chain ceramides are among the most hydrophobic molecules in Nature, they are totally insoluble in water and they hardly mix with phospholipids in membranes, giving rise to ceramide-enriched domains. In situ enzymic generation, or external addition, of long-chain ceramides in membranes has at least three important effects: (i) the lipid monolayer tendency to adopt a negative curvature, e.g. through a transition to an inverted hexagonal structure, is increased, (ii) bilayer permeability to aqueous solutes is notoriously enhanced, and (iii) transbilayer (flip-flop) lipid motion is promoted. Short-chain ceramides mix much better with phospholipids, promote a positive curvature in lipid monolayers, and their capacities to increase bilayer permeability or transbilayer motion are very low or non-existent.

Postprandial Activation of Coagulant Factor VII by Long-chain Dietary Fatty Acids

1996 ◽  
Vol 76 (03) ◽  
pp. 369-371 ◽  
Author(s):  
T A B Sanders ◽  
G J Miller ◽  
Tamara de Grassi ◽  
Najat Yahia
Keyword(s):  
Fatty Acids ◽  
Dietary Fatty Acids ◽  
Factor Vii ◽  
Fat Intake ◽  
Long Chain Fatty Acids ◽  
Postprandial Lipaemia ◽  
Increased Risk ◽  
Coagulant Activity ◽  
Long Chain Triglycerides ◽  
Long Chain

SummaryFactor VII coagulant activity (FVIIc) is associated with an increased risk of fatal ischaemic heart disease (IHD). Several reports have suggested that dietary fat intake or hypertriglyceridaemia are associated with elevated levels of FVII. This study demonstrates that an intake of long-chain fatty acids sufficient to induce postprandial lipaemia in healthy subjects leads to a substantial elevation in both FVIIc and the concentration of FVII circulating in the activated form. Such an increase in FVIIc could not be induced by medium-chain triglycerides. These results suggest that the consumption of a sufficient amount of long-chain triglycerides to induce postprandial lipaemia induces the activation of FVII.

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