Which enzyme converts methylmalonyl CoA to succinyl-CoA?

Which enzyme converts methylmalonyl CoA to succinyl-CoA?

Methylmalonyl CoA synthase
Methylmalonyl CoA synthase requires vitamin B12 as a cofactor and is used to convert methylmalonyl CoA to succinyl CoA.

How succinyl-CoA is formed in TCA cycle?

Sources. It is an important intermediate in the citric acid cycle, where it is synthesized from α-ketoglutarate by α-ketoglutarate dehydrogenase through decarboxylation. Succinyl-CoA is first converted to malate, and then to pyruvate where it is then transported to the matrix to enter the citric acid cycle.

How is propionyl CoA converted to succinyl-CoA?

The oxidation of the side chain of cholesterol also yields propionyl-CoA. Thus, propionyl-CoA is derived from the catabolism of lipids and proteins. Propionyl-CoA is converted to succinyl-CoA, which is oxidized or converted to glucose by way of oxaloacetate and pyruvate (gluconeogenesis; Chapter 14).

Which type of reaction occurs when succinyl-CoA is converted to succinate in the citric acid cycle?

level phosphorylation
Reaction 5: The conversion of succinyl-CoA to succinate The conversion of succinyl-CoA to succinate yields the only high-energy phosphate bond to be formed directly in the course of the cycle. This reaction is an example of a substrate level phosphorylation (page 228).

What does Methylmalonyl CoA inhibit?

Abstract. Methylmalonyl-CoA inhibited fatty acid synthesis from acetyl-CoA and malonyl-CoA by the fatty acid synthetose system in the microsomalfrec supernatant fraction of rat liver. Methylmalonyl-CoA itself was incorporated into fatty acids to produce two unusual fatty acids, which may be branched chain.

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).

How is succinyl-CoA formed?

Formation. Succinyl CoA can be formed from methylmalonyl CoA through the utilization of deoxyadenosyl-B12 (deoxyadenosylcobalamin) by methylmalonyl CoA Mutase. This reaction, which requires vitamin B12 to occur, is important in the catabolism of some branched-chain amino acids as well as odd-chain fatty acids.

What is reaction involved in succinyl-CoA to succinate?

Succinyl CoA synthetase catalyzes the following reversible reaction: Succinyl CoA + Pi + NDP ↔ Succinate + CoA + NTP. The enzyme then utilizes a histidine residue to remove the phosphate group from succinyl phosphate and generate succinate.

How does propionyl-CoA enter the citric acid cycle?

Within the citric acid cycle in humans, propionyl-CoA, which interacts with oxaloacetate to form methylcitrate, can also catalyzed into methylmalonyl-CoA through carboxylation by propionyl-CoA carboxylase (PCC). Methylmalonyl-CoA is later transformed to succinyl-CoA to be further used in the tricarboxylic acid cycle.

How does propionyl-CoA enters into TCA cycle?

Metabolic pathway. Propionyl-CoA carboxylase (PCC) catalyzes the conversion of propionyl-CoA to methylmalonyl-CoA, which enters the Krebs cycle via succinyl-CoA. Sources of propionate include: valine, isoleucine, threonine, methionine, odd-chain fatty acids, and cholesterol.

What type of reaction is the citric acid cycle?

The citric acid cycle, shown in —also known as the tricarboxylic acid cycle (TCA cycle) or the Krebs cycle—is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate—derived from carbohydrates, fats, and proteins—into carbon dioxide.

What type of reaction does Succinyl CoA synthetase catalyze?

citric acid cycle reaction
Succinyl-CoA synthetase directly catalyzes a citric acid cycle reaction that produces . Succinyl-CoA synthetase is produced by the reaction catalyzed by alpha-ketoglutarate dehydrogenase.

How is L-methylmalonyl CoA isomerized into succinyl CoA?

The resulting compound is isomerized into L-methylmalonyl-CoA via methylmalonyl-CoA epimerase. A vitamin B12-dependent enzyme, called methylmalonyl CoA mutase catalyzes the rearrangement of L-methylmalonyl-CoA to succinyl-CoA, which is an intermediate of the citric acid cycle.

What is methylmalonyl-CoA mutase (MCM)?

Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. 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.

What is the pathophysiology of methylmalonyl-CoA toxicity?

The pathway involves the formation of propionyl-CoA and its conversion to methylmalonyl-CoA before the formation of succinyl-CoA. Affected newborns are characterized by recurrent vomiting, hepatomegaly, and developmental retardation owing to accumulation of methylmalonic acid.

How does methylmalonyl-CoA enter the Krebs cycle?

Methylmalonyl-CoA is formed from propionyl-CoAby propionyl-CoA carboxylaseby help of biotin(vitamin B7). It is converted into succinyl-CoAby methylmalonyl-CoA mutase, in a reaction that requires vitamin B12as a cofactor. In this way, it enters the Krebs cycle.