Methylcrotonyl-CoA: Difference between revisions

Revision as of 20:31, 30 December 2024

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

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.

Pathway

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

External links

Methylcrotonyl-CoA on WikiMD

@@ 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}}