Folate-dependent enzymes in thymidylate and purine synthesis

Folate-dependent enzymes in thymidylate and purine synthesis are a group of metabolic enzymes, including dihydrofolate reductase (DHFR), thymidylate synthase (TYMS), and glycinamide ribonucleotide transformylase (GART), that are essential for the production of DNA and RNA precursors (UniProt, 2024). These enzymes utilize folate derivatives as cofactors to transfer one-carbon units during the de novo biosynthesis of thymidine and purine nucleotides (PubMed, 2004). Because DNA replication is highly dependent on a steady supply of these nucleotides, these enzymes are critical for cell proliferation and are often upregulated in malignant cells (StatPearls, 2023). Consequently, they serve as primary targets for antifolate chemotherapy agents such as methotrexate and pemetrexed, which competitively inhibit enzyme activity to induce "thymineless death" (PubChem, 2024). Beyond oncology, these enzymes are targeted in the treatment of autoimmune disorders like rheumatoid arthritis and in the development of antimicrobial agents that exploit differences between human and microbial folate metabolism (PubMed, 2004). Therapeutic challenges associated with these targets include the development of drug resistance through enzyme upregulation or mutations in folate transporters (StatPearls, 2023). Monitoring biomarkers like TYMS expression levels or MTHFR polymorphisms can help clinicians predict patient response and manage potential toxicities such as myelosuppression (PubMed, 2004). Overall, this enzyme group remains a cornerstone of pharmacological intervention in diseases characterized by pathological cell growth.

Other names

Folate metabolism enzymesOne-carbon metabolism enzymesAntifolate targetsNucleotide biosynthesis enzymes

Inhibition of these enzymes prevents the synthesis of thymidylate and purine nucleotides by depleting reduced folate pools or blocking one-carbon transfer, leading to the inhibition of DNA synthesis and repair (StatPearls, 2023; PubMed, 2004).