very long-chain fatty-acyl-CoA metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving very long-chain fatty-acyl-CoAs, any derivative of coenzyme A in which the sulfhydryl group is in a thioester linkage with a very long-chain fatty-acyl group. A very long-chain fatty acid has an aliphatic tail containing more than 22 carbons. [GOC:pm]

Very long-chain fatty-acyl-CoA metabolic process is a crucial aspect of lipid metabolism, primarily involving the breakdown and synthesis of fatty acids with chain lengths exceeding 22 carbons. These very long-chain fatty acids (VLCFAs) are primarily derived from dietary sources or synthesized de novo by the organism.

**Breakdown (β-oxidation):**

* **Transport:** VLCFAs are first transported into mitochondria, the cellular powerhouses, through a specialized transport system involving carnitine palmitoyltransferase 1 (CPT1) and carnitine acylcarnitine translocase (CACT).
* **Activation:** Upon entering the mitochondria, VLCFAs are activated by attaching them to coenzyme A (CoA), forming very long-chain acyl-CoA.
* **β-oxidation:** The activated VLCFAs undergo a series of four enzymatic reactions (dehydrogenation, hydration, oxidation, and thiolysis) that cleave two carbon units at a time from the carboxyl end, generating acetyl-CoA and a shortened fatty acyl-CoA. This process continues until the VLCFA is completely broken down into acetyl-CoA.

**Synthesis:**

* **Elongation:** VLCFAs are synthesized by the sequential addition of two-carbon units from malonyl-CoA to the carboxyl end of a pre-existing fatty acyl-CoA. This process occurs primarily in the endoplasmic reticulum and involves a series of elongases specific for different chain lengths.

**Regulation:**

* **Substrate availability:** The availability of VLCFAs in the diet or de novo synthesis influences the rate of VLCFA metabolism.
* **Hormonal regulation:** Hormones like insulin and glucagon influence VLCFA metabolism by affecting the expression and activity of enzymes involved in their breakdown and synthesis.

**Physiological significance:**

* **Energy production:** VLCFA breakdown provides ATP, the cellular energy currency.
* **Membrane structure:** VLCFAs are essential components of cell membranes, contributing to their structural integrity and fluidity.
* **Signal transduction:** Some VLCFAs act as signaling molecules, regulating cellular processes.

**Clinical relevance:**

* **Genetic disorders:** Mutations in genes involved in VLCFA metabolism can lead to various genetic disorders, such as adrenoleukodystrophy and Zellweger syndrome.
* **Dietary intake:** Dietary VLCFAs are important for various metabolic functions, and their deficiency or excess can have health implications.

Overall, very long-chain fatty-acyl-CoA metabolic process is a complex and vital process that plays a critical role in lipid metabolism, energy production, and cellular function.'
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Proteins (1)

Compounds (1)