Lipid linked desaturation

LIPIDS OF CHLAMYD.QMQNAS REINHARDTII INCORPORATION OF X-ACETATE, PALMITATE AND OLEATE INTO DIFFERENT LIPIDS AND EVIDENCE FOR LIPID-LINKED DESATURATION OF FATTY ACIDS... 

The labelling kinetics of fatty acids and molecular species strongly supports the general view of a lipid-linked desaturation in which every lipid class is individually involved. 

The synthetic compound, l,2-di-0-9 -octadecenyl-3-0-/3-D-galactopyranosyl-5n-glycerol, which is an ether analogue of mono-D-galactosyldiacylglycerol, can be converted by plant enzymes into the 6-O-acyl derivative.The availability of the 9-octadecenyl compound can provide a substrate for studies on the direct desaturation of lipid-linked acyl or alkyl chains. 

Once an alkoxy derivahve of dihydroxyacetone is formed, reduchon fo fhe 2-OH form, further acylation, and conversion to various alkyl phospholipids and neutral lipids can occur. The pathways (Eq. 21-12, steps b-f) are closely akin to those of Fig. 21-4. The conversion of alkoxy lipids fo plasmalogens occurs by oxidative desaturation (Eq. 21-12, step/). ° The initial steps in the S5mthesis of efher-linked lipids take place principally in the peroxisomes. Enzymes catalyzing both the acylation of dihydroxyacetone phosphate and the S5mthesis of alkyl-dihydroxyacetone-P (step a, Eq. 

Lowering growth temperature has been widely shown to Increase fatty acid desaturation in the membrane lipids of higher plant tissue and has been linked to the retention of membrane fluidity although it may merely reflect Increased oxygen solubility at lower temperatures . The few studies on marine algae show similar effects . ... 

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