What is Methylmalonyl CoA Mutase deficiency?
What is Methylmalonyl CoA Mutase deficiency?
Methylmalonyl-Coenzyme A mutase deficiency (MCM deficiency) is a type of methylmalonic acidemia caused by having too little methylmalonyl-CoA mutase. Methylmalonyl-CoA mutase (MCM) is one of the special proteins (enzymes) needed to breakdown certain amino acids found in the food we eat.
Why can B12 deficiency mimic a deficiency in MUT?
When the amount of B12 is insufficient for the conversion of cofactor methylmalonyl-CoA into succinyl-CoA, the buildup of unused methylmalonyl-CoA eventually leads to methylmalonic acidemia. This diagnosis is often used as an indicator of vitamin B12 deficiency in serum.
What does methylmalonyl-CoA do?
Methylmalonyl-CoA is the thioester consisting of coenzyme A linked to methylmalonic acid. It is an important intermediate in the biosynthesis of succinyl-CoA, which plays an essential role in the tricarboxylic acid cycle (aka the Citric Acid Cycle, or Krebs Cycle).
What causes MUT?
MUT is an autosomal recessive genetic conditionAn illness caused by abnormalities in genes or chromosomes. This means that a child must inheritTo receive from one’s parents by genetic transmission two copies of the non-working geneThe instructions inside each cell.
What is the role of the coenzyme vitamin B12 in the reaction catalyzed by Methylmalonyl-CoA Mutase?
This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate.
Where does propionyl-CoA come from?
Important sources of propionyl-CoA are the catabolism of isoleucine, valine, methionine, and threonine (Chapter 17). Cholesterol side chain oxidation also yields propionyl-CoA. Thus, propionyl-CoA is derived from the catabolism of lipids and proteins.
Which is the gene for methylmalonyl-CoA mutase?
Methylmalonyl-CoA mutase (MCM), mitochondrial, also known as methylmalonyl-CoA isomerase, is a protein that in humans is encoded by the MUT gene.
Which is enzyme converts methylmalonyl CoA to R?
The MCEE gene encodes an enzyme that interconverts D- and L- methylmalonyl-CoA during the degradation of branched-chain amino acids, odd chain-length fatty acids, and other metabolites. In biochemistry terms, it catalyzes the reaction that converts ( S )- methylmalonyl-CoA to the ( R) form. This enzyme catalyses the following chemical reaction
Is the homolytic reaction of methylmalonyl CoA unusual?
The homolytic reaction is unusual in biology, as is the presence of a metal-carbon bond. Methylmalonyl-CoA mutase is a member of the isomerase subfamily of adenosylcobalamin-dependent enzymes. Furthermore, it is classified as class I, as it is a ‘DMB-off’/’His-on’ enzyme.
Which is a cofactor of methylmalonyl CoA in MCM?
MCM catalyzes the reversible isomerisation of l‐methylmalonyl‐CoA to succinyl‐CoA, requiring cobalamin (vitamin B12) in the form of adenosylcobalamin (AdoCbl) as a cofactor.
