Vitamin B12-dependent enzymes (Methionine synthase and Methylmalonyl-CoA mutase) (B12-dependent enzymes)

Vitamin B12-dependent enzymes, specifically methionine synthase (MTR) and methylmalonyl-CoA mutase (MUT), are critical for the maintenance of the central and peripheral nervous systems (StatPearls, 2023). Methionine synthase is required for the synthesis of methionine and S-adenosylmethionine, which are essential for the methylation of myelin basic protein, a key component of the myelin sheath (NIH, 2024). Methylmalonyl-CoA mutase is involved in the catabolism of certain amino acids and fatty acids; its dysfunction leads to the accumulation of methylmalonic acid, which is neurotoxic and disrupts myelin lipid metabolism (PubMed, PMID: 22223356). Deficiencies in these enzymatic pathways result in clinical conditions such as peripheral neuropathy and subacute combined degeneration of the spinal cord (Wikipedia, Vitamin B12 deficiency). Therapeutic intervention involves the administration of cobalamin (Vitamin B12) to restore enzyme activity and prevent permanent neurological damage (PubChem, CID 16212801). Monitoring of biomarkers like methylmalonic acid and homocysteine is essential for diagnosing deficiency and assessing treatment efficacy (Mayo Clinic, 2023).

Other names

Cobalamin-dependent enzymesMethionine synthase (MTR)Methylmalonyl-CoA mutase (MUT)5-methyltetrahydrofolate-homocysteine methyltransferaseMethylmalonyl-CoA isomeraseMMUTB12-dependent metabolic pathways

Vitamin B12 derivatives act as essential cofactors for methionine synthase and methylmalonyl-CoA mutase, restoring the metabolic flux of the methionine and propionate pathways, thereby facilitating myelin repair and reducing neurotoxic metabolite levels (StatPearls, 2023; NIH, 2024).