Related Experiment Video
Updated: Apr 21, 2026
06:45
Author Spotlight: Optimizing Hollow-Fiber Membranes for Continuous Liquid-Liquid Extraction of Medium-Chain Fatty Acids
Published on: August 9, 2024
1.9K
Visualizing the chain-flipping mechanism in fatty-acid biosynthesis
Joris Beld1, Hu Cang, Michael D Burkart
1Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358 (USA).
Angewandte Chemie (International Ed. in English)
|October 30, 2014
Summary
Researchers visualized the fatty acid synthesis chain-flipping mechanism using fluorescent probes. This revealed how acyl carrier protein (ACP) interacts with ketoacyl synthase (KASII) in Escherichia coli.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Fatty acid synthases (FAS) are crucial for cellular lipid production.
- The acyl carrier protein (ACP) within FAS sequesters growing fatty acid chains.
- The precise mechanism of cargo transfer and chain-flipping within ACP is not fully understood.
Purpose of the Study:
- To elucidate the dynamic mechanism of cargo sequestration and release by ACP.
- To visualize the chain-flipping process during fatty acid elongation.
- To demonstrate the specificity between ACP and its catalytic partners.
Main Methods:
- Utilized solvatochromic pantetheine probes attached to ACP to monitor cargo sequestration via fluorescence.
- Employed a dual solvatochromic cross-linking probe for confirmation.
- Applied solution-phase NMR spectroscopy to analyze molecular interactions.
- Visualized the mechanism using single-molecule fluorescence techniques.
Main Results:
- Fluorescent probes indicated cargo sequestration within ACP's hydrophobic core.
- Addition of a catalytic partner enhanced fluorescence, signifying cargo release.
- Confirmed chain-flipping mechanism and ACP-KASII specificity.
- Visualized the dynamic chain-flipping process at the single-molecule level.
Conclusions:
- The study successfully visualized the elusive chain-flipping mechanism in fatty acid synthesis.
- Demonstrated the specific interaction between Escherichia coli ACP and its partner KASII.
- Highlighted the utility of solvatochromic probes for studying dynamic enzymatic processes.
Related Concept Videos
01:28Overview of Fatty Acid Metabolism
25.3K
Lipids also are sources of energy that power cellular processes. Like carbohydrates, lipids are composed of carbon, hydrogen, and oxygen, but these atoms are arranged differently. Most lipids are nonpolar and hydrophobic. Major types include fats and oils, waxes, phospholipids, and steroids.
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
25.3K
01:25Lipid Catabolism
1.4K
Triglycerides serve as crucial long-term energy storage molecules in microorganisms, providing a dense source of metabolic energy. Their breakdown is mediated by lipases, which hydrolyze triglycerides into glycerol and free fatty acids. Each of these components follows distinct metabolic pathways, ultimately contributing to ATP synthesis and cellular energy homeostasis.Glycerol MetabolismGlycerol, released from triglyceride hydrolysis, is phosphorylated by glycerol kinase to form...
1.4K
01:06Fats as Energy Storage Molecules
18.5K
Triglycerides are a form of long-term energy storage molecules. They are made of glycerol and three fatty acids. To obtain energy from fat, triglycerides must first be broken down by hydrolysis into their two principal components, fatty acids and glycerol. This process, called lipolysis, takes place in the cytoplasm. The resulting fatty acids are oxidized by β-oxidation into acetyl-CoA, which is used by the Krebs cycle. The glycerol that is released from triglycerides after lipolysis...
18.5K
01:29Biosynthesis of Lipids
925
Microbial membranes exhibit remarkable diversity in lipid composition, reflecting evolutionary adaptations to various environmental conditions. The three domains of life—Bacteria, Archaea, and Eukarya—synthesize membrane lipids through distinct biosynthetic pathways, leading to fundamental structural differences that impact membrane stability, function, and adaptability.Fatty Acid-Based Lipids in Bacteria and EukaryaBacteria and eukaryotes share a common fatty acid biosynthesis...
925
01:28The Citric Acid Cycle: Output
8.7K
The citric acid cycle is termed an amphibolic pathway as it operates both anabolically and catabolically. The cyclic reactions balance the flux of the substrates to provide an optimal concentration of NADH and ATP to the cell.
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is...
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is...
8.7K
01:29Amino Acid Biosynthetic Pathways
1.7K
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which...
1.7K