Substrate specificities in ether lipid biosynthesis. Metabolism of polyunsaturated fatty acids and alcohols by rat brain microsomes
20
Citation
23
Reference
10
Related Paper
Citation Trend
Hydroxylation
Cite
Citations (19)
Sphingidae
Hemolymph
Cite
Citations (52)
Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed the Octopus vulgaris Scd is a ∆9 desaturase with relatively high affinity towards saturated FAs with ≥ C18 chain lengths. Scd was unable to desaturate 20:1n-15 (∆520:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at ∆9 position. Interestingly, the previously characterised ∆5 fatty acyl desaturase was indeed able to convert 20:1n-9 (∆1120:1) to ∆5,1120:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs.
Fatty acid desaturase
Cite
Citations (44)
Carboxylation
Specific activity
Cite
Citations (38)
Cite
Citations (27)
The carbocyclic analogues of phosphoribosylamine, glycinamide ribonucleotide, and formylglycinamide ribonucleotide have been prepared enantiospecifically from D-ribonic acid gamma-lactone. These carbocycles, which have the same absolute configuration as the natural D-ribose-derived intermediates of de novo purine biosynthesis, are utilized stoichiometrically by the initial enzymes of the pathway. A comparison of the enzymatic processing of the (-)-enantiomers with those of the racemates indicates that in some cases, the (+)-enantiomer acts to inhibit the enzymatic activity.
Purine metabolism
De novo synthesis
Ribonucleotide
Stereoisomerism
Ribose
Cite
Citations (12)
1. p-Nitrophenyl pent-1-yl ether was metabolized (65–70%) in the presence of liver microsomes from phenobarbital-treated rats to give the 4-(major), 3-(minor), and 2-hydroxypent-1-yl (minor) derivatives which were characterized by g.l.c.-mass spectrometry; O-dealkylation (reflecting 1-hydroxylation) and 5-hydroxylation did not occur to a significant extent.2. 5,5,5-Trifluorination of the pent-1-yl group markedly reduced the extent of metabolism (to ∼10%).3. p-Nitrophenyl 2,2,2-trifluoroethyl ether was virtually completely resistant to microsomal metabolism under conditions where the ethyl analogue was extensively O-dealkylated.
Cite
Citations (4)
[Objective] This study established a LC-MS/MS method for the determination of squamocin and bullatacin, and calculated their enzyme kinetics in rat microsome. [Method] Established microsome incubation system, determined the remaining concentration of substrate at different time points after starting the reaction, and calculated enzyme kinetic parameters with substrate depletion method. [Result] In rat microsome, the apparent KM of squamocin and bullatacin were (1.6±0.5) μmol/L and(2.0±0.4) μmol/L.[Conclusion] This method was suitable for the enzyme kinetic study of squamocin and bullatacin.
Enzyme Kinetics
Cite
Citations (0)
Identification
Moiety
Cite
Citations (10)