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Updated: May 17, 2025
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Analysis of Neutral Lipid Synthesis in Saccharomyces cerevisiae by Metabolic Labeling and Thin Layer Chromatography
Published on: February 2, 2021
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Counting modes of acyl-lipid desaturases
Alexander Y Starikov1, Roman A Sidorov1, Dmitry A Los1
1K. A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya Street 35, Moscow 127276, Russian Federation.
Functional Plant Biology : FPB
|April 4, 2025
Summary
Fatty acid desaturases (FADs) are enzymes crucial for cell membranes. New research shows plant and cyanobacterial FADs count from existing double bonds, not chain ends, for fatty acid modification.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Fatty acid desaturases (FADs) are essential oxygen-dependent enzymes.
- FADs introduce double bonds into fatty acids, altering membrane properties vital for cellular functions.
- These enzymes are highly conserved across diverse organisms and exhibit substrate specificity.
Purpose of the Study:
- To elucidate the precise regiospecificity and counting mechanisms of various fatty acid desaturases.
- To clarify the reference point used by acyl-lipid Δ12-FADs (ω6-FADs) in plants and cyanobacteria.
- To provide a foundation for understanding FAD activity and engineering polyunsaturated fatty acid biosynthesis.
Main Methods:
- Heterologous expression of FADs in model organisms (yeast, cyanobacteria).
- Supplementation with exogenous monounsaturated odd- and even-chain fatty acids.
- Analysis of newly synthesized fatty acid products to determine desaturase activity and specificity.
Main Results:
- Plant and cyanobacterial acyl-lipid Δ12-FADs do not count from the carboxyl or methyl end of fatty acids.
- These Δ12-FADs count three carbons from an existing double bond in the precursor, regardless of chain length.
- Δ6-FADs and ω3-FADs (Δ15-FADs) count from the carboxyl terminus.
Conclusions:
- The counting mechanism of FADs is more complex than previously assumed, with different enzymes using distinct reference points.
- Acyl-lipid Δ12-FADs in plants and cyanobacteria utilize an internal reference point for desaturation.
- Understanding these precise mechanisms is critical for manipulating fatty acid biosynthesis pathways.
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