Methylcrotonyl-CoA: Difference between revisions

Latest revision as of 05:07, 3 March 2025

Overview of Methylcrotonyl-CoA

Methylcrotonyl-CoA

Methylcrotonyl-CoA is an intermediate in the leucine degradation pathway. It is involved in the metabolism of branched-chain amino acids.

Function[edit]

Methylcrotonyl-CoA is converted to 3-methylglutaconyl-CoA by the enzyme methylcrotonyl-CoA carboxylase (MCC). This reaction requires biotin as a cofactor and is an essential step in the catabolism of leucine.

Clinical significance[edit]

Deficiency in methylcrotonyl-CoA carboxylase activity can lead to a metabolic disorder known as 3-Methylcrotonyl-CoA carboxylase deficiency. This condition is characterized by the accumulation of toxic metabolites, which can cause symptoms such as hypotonia, developmental delay, and metabolic acidosis.

Pathway[edit]

The leucine degradation pathway involves several steps:

Leucine is first transaminated to α-ketoisocaproate.
α-Ketoisocaproate is then oxidatively decarboxylated to form isovaleryl-CoA.
Isovaleryl-CoA is converted to methylcrotonyl-CoA.
Methylcrotonyl-CoA is carboxylated to form 3-methylglutaconyl-CoA.
Further steps lead to the production of acetyl-CoA and acetoacetate, which enter the citric acid cycle and ketogenesis, respectively.

References[edit]

External links[edit]

Methylcrotonyl-CoA on WikiMD

Methylcrotonyl coenzyme A

@@ Line 1: / Line 1: @@
-'''Methylcrotonyl-CoA''' is a key intermediate in the [[metabolism]] of [[leucine]], an essential [[amino acid]]. It is produced from [[3-methylcrotonyl-CoA]] by the enzyme [[3-methylcrotonyl-CoA carboxylase]], and is further metabolized to [[HMG-CoA]] by the enzyme [[methylcrotonyl-CoA dehydrogenase]].
-== Metabolism ==
+{{Short description|Overview of Methylcrotonyl-CoA}}
+{{Infobox enzyme
+| name = Methylcrotonyl-CoA carboxylase
+| image = <!-- Image of the enzyme, if available -->
+| width =
+| caption =
+| EC_number = 6.4.1.4
+| CAS_number = 9027-96-2
+| GO_code = 0004492
+}}
-The metabolism of Methylcrotonyl-CoA is a part of the larger [[leucine catabolism]] pathway. The first step in this process is the conversion of leucine to [[alpha-ketoisocaproate]] by the enzyme [[branched-chain amino acid aminotransferase]]. Alpha-ketoisocaproate is then decarboxylated to [[isovaleryl-CoA]] by the enzyme [[alpha-ketoacid dehydrogenase]]. Isovaleryl-CoA is subsequently converted to [[methylcrotonyl-CoA]] by the enzyme [[isovaleryl-CoA dehydrogenase]].
+'''Methylcrotonyl-CoA''' is an intermediate in the [[leucine]] degradation pathway. It is involved in the [[metabolism]] of [[branched-chain amino acids]].
-Methylcrotonyl-CoA is then carboxylated by the enzyme [[3-methylcrotonyl-CoA carboxylase]] to form [[3-methylglutaconyl-CoA]]. This is followed by the hydration of 3-methylglutaconyl-CoA to [[3-hydroxy-3-methylglutaryl-CoA]] (HMG-CoA) by the enzyme [[methylglutaconyl-CoA hydratase]]. HMG-CoA is then cleaved by the enzyme [[HMG-CoA lyase]] to form [[acetoacetate]] and [[acetyl-CoA]], which can be further metabolized in the [[citric acid cycle]].
+== Function ==
+Methylcrotonyl-CoA is converted to [[3-methylglutaconyl-CoA]] by the enzyme [[methylcrotonyl-CoA carboxylase]] (MCC). This reaction requires [[biotin]] as a cofactor and is an essential step in the catabolism of leucine.
 == Clinical significance ==
+Deficiency in methylcrotonyl-CoA carboxylase activity can lead to a metabolic disorder known as [[3-Methylcrotonyl-CoA carboxylase deficiency]]. This condition is characterized by the accumulation of toxic metabolites, which can cause symptoms such as [[hypotonia]], [[developmental delay]], and [[metabolic acidosis]].
-Deficiencies in the enzymes involved in the metabolism of Methylcrotonyl-CoA can lead to various metabolic disorders. For example, a deficiency in [[3-methylcrotonyl-CoA carboxylase]] can lead to [[3-Methylcrotonylglycinuria]], a rare inherited disorder characterized by an inability to properly process certain proteins.
+== Pathway ==
+The leucine degradation pathway involves several steps:
-[[File:Leucine metabolism.png|thumb|right|300px|Leucine metabolism. Methylcrotonyl-CoA is shown in the middle of the diagram.]]
+* Leucine is first transaminated to [[α-ketoisocaproate]].
+* α-Ketoisocaproate is then oxidatively decarboxylated to form [[isovaleryl-CoA]].
+* Isovaleryl-CoA is converted to methylcrotonyl-CoA.
+* Methylcrotonyl-CoA is carboxylated to form 3-methylglutaconyl-CoA.
+* Further steps lead to the production of [[acetyl-CoA]] and [[acetoacetate]], which enter the [[citric acid cycle]] and [[ketogenesis]], respectively.
 == See also ==
+* [[Leucine metabolism]]
-* [[Leucine]]
+* [[Branched-chain amino acid metabolism]]
-* [[Metabolism]]
+* [[Biotin-dependent carboxylases]]
-* [[3-Methylcrotonylglycinuria]]
 == References ==
+{{Reflist}}
-{{reflist}}
+== External links ==
+* [https://www.wikimd.com/wiki/Methylcrotonyl-CoA Methylcrotonyl-CoA on WikiMD]
 [[Category:Metabolism]]
+[[Category:Enzymes]]
 [[Category:Biochemistry]]
-[[Category:Coenzymes]]
+[[Category:Genetic disorders]]
-{{medicine-stub}}
+<gallery>
+File:Methylcrotonyl coenzyme A.svg|Methylcrotonyl coenzyme A
+</gallery>