Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biochem J. 2002 Jun 1;364(Pt 2):393-401.

Control analysis of lipid biosynthesis in tissue cultures from oil crops shows that flux control is shared between fatty acid synthesis and lipid assembly.

Author information

  • 1School of Biosciences, Cardiff University, P.O. Box 911, Cardiff CF10 3US, Wales, UK.

Abstract

Top-Down (Metabolic) Control Analysis (TDCA) was used to examine, quantitatively, lipid biosynthesis in tissue cultures from two commercially important oil crops, olive (Olea europaea L.) and oil palm (Elaeis guineensis Jacq.). A conceptually simplified system was defined comprising two blocks of reactions: fatty acid synthesis (Block A) and lipid assembly (Block B), which produced and consumed, respectively, a common and unique system intermediate, cytosolic acyl-CoA. We manipulated the steady-state levels of the system intermediate by adding exogenous oleic acid and, using two independent assays, measured the effect of the addition on the system fluxes (J(A) and J(B)). These were the rate of incorporation of radioactivity: (i) through Block A from [1-(14)C]acetate into fatty acids and (ii) via Block B from [U-(14)C]glycerol into complex lipids respectively. The data showed that fatty acid formation (Block A) exerted higher control than lipid assembly (Block B) in both tissues with the following group flux control coefficients (C):(i) Oil palm: *C(J(TL))(BlkA)=0.64+/-0.05 and *C(J(TL))(BlkB)=0.36+/-0.05(ii) Olive: *C(J(TL))(BlkA)=0.57+/-0.10 and *C(J(TL))(BlkB)=0.43+/-0.10where *C indicates the group flux control coefficient over the lipid biosynthesis flux (J(TL)) and the subscripts BlkA and BlkB refer to defined blocks of the system, Block A and Block B. Nevertheless, because both parts of the lipid biosynthetic pathway exert significant flux control, we suggest strongly that manipulation of single enzyme steps will not affect product yield appreciably. The present study represents the first use of TDCA to examine the overall lipid biosynthetic pathway in any tissue, and its findings are of immediate academic and economic relevance to the yield and nutritional quality of oil crops.

PMID:
12023882
[PubMed - indexed for MEDLINE]
PMCID:
PMC1222584
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Portland Press Icon for PubMed Central
    Loading ...
    Write to the Help Desk