D-methylmalonyl-CoA

Definition

D-methylmalonyl-CoA is an important intermediate in the catabolism of certain amino acids and odd-chain fatty acids. It is a key metabolite involved in the process of β-oxidation, which is the breakdown of fatty acids to produce energy for the body.

5 Must Know Facts For Your Next Test

1. D-methylmalonyl-CoA is formed from the conversion of propionyl-CoA, which is produced during the catabolism of odd-chain fatty acids and certain amino acids.
2. The enzyme methylmalonyl-CoA mutase catalyzes the conversion of D-methylmalonyl-CoA to succinyl-CoA, which can then enter the citric acid cycle.
3. Deficiencies in the methylmalonyl-CoA mutase enzyme or its cofactor, vitamin B12, can lead to the accumulation of D-methylmalonyl-CoA and cause the genetic disorder methylmalonic acidemia.
4. D-methylmalonyl-CoA is an important intermediate in the breakdown of the amino acids isoleucine, valine, threonine, and methionine, as well as odd-chain fatty acids.
5. The presence of D-methylmalonyl-CoA in the body can be used as a biomarker for the diagnosis and monitoring of certain metabolic disorders.

Review Questions

• Explain the role of D-methylmalonyl-CoA in the catabolism of triacylglycerols through β-oxidation.
  • D-methylmalonyl-CoA is an important intermediate in the β-oxidation pathway, which is the process of breaking down fatty acids to generate energy. During the catabolism of odd-chain fatty acids, propionyl-CoA is produced, which is then converted to D-methylmalonyl-CoA. The enzyme methylmalonyl-CoA mutase then catalyzes the conversion of D-methylmalonyl-CoA to succinyl-CoA, which can enter the citric acid cycle and be used to generate ATP. The presence of D-methylmalonyl-CoA in this pathway is crucial for the complete breakdown and utilization of odd-chain fatty acids derived from triacylglycerols.
• Describe how a deficiency in the methylmalonyl-CoA mutase enzyme or vitamin B12 can lead to the accumulation of D-methylmalonyl-CoA and cause metabolic disorders.
  • A deficiency in the methylmalonyl-CoA mutase enzyme or its cofactor, vitamin B12, can impair the conversion of D-methylmalonyl-CoA to succinyl-CoA. This leads to the accumulation of D-methylmalonyl-CoA, which can disrupt normal metabolic processes and cause the genetic disorder methylmalonic acidemia. In this condition, the buildup of D-methylmalonyl-CoA and other toxic metabolites can lead to a range of symptoms, including developmental delays, seizures, and life-threatening metabolic crises. Proper enzyme function and adequate vitamin B12 levels are crucial for maintaining the appropriate levels of D-methylmalonyl-CoA and preventing the onset of such metabolic disorders.
• Analyze the significance of D-methylmalonyl-CoA as a biomarker for the diagnosis and monitoring of certain metabolic disorders, and explain how this information can be used to guide clinical management.
  • The presence of elevated levels of D-methylmalonyl-CoA in the body can serve as a valuable biomarker for the diagnosis and monitoring of various metabolic disorders, such as methylmalonic acidemia. By measuring the concentration of D-methylmalonyl-CoA, clinicians can identify disruptions in the normal metabolic pathways involving this intermediate. This information can then be used to guide the diagnosis, treatment, and ongoing management of these conditions. For example, if D-methylmalonyl-CoA levels are found to be high, it may indicate a deficiency in the methylmalonyl-CoA mutase enzyme or a vitamin B12 deficiency, which would inform the appropriate interventions, such as enzyme replacement therapy or vitamin supplementation. Monitoring D-methylmalonyl-CoA levels can also help track the effectiveness of treatment and make necessary adjustments to ensure optimal metabolic function and patient outcomes.

Related terms

β-Oxidation: The catabolic process that breaks down fatty acids to produce acetyl-CoA, which can then enter the citric acid cycle to generate ATP.

Odd-chain Fatty Acids: Fatty acids that contain an odd number of carbon atoms, which require a different metabolic pathway for degradation compared to even-chain fatty acids.

Propionyl-CoA:

An intermediate produced during the breakdown of certain amino acids and odd-chain fatty acids, which is then converted to D-methylmalonyl-CoA.