Purine synthesis and nucleic acid synthesis enzymes

Purine synthesis and nucleic acid synthesis enzymes encompass a broad array of proteins involved in the de novo and salvage pathways of nucleotide production, as well as the assembly of DNA and RNA. Key members of this group include dihydrofolate reductase (DHFR), inosine-5'-monophosphate dehydrogenase (IMPDH), and ribonucleotide reductase (RNR), which are vital for providing the precursors required for cellular replication (Source: NIH, PubChem). Because these enzymes are indispensable for cell division, they serve as critical targets for antimetabolite drugs used in cancer chemotherapy and immunosuppression (Source: PubMed). For instance, methotrexate inhibits DHFR to deplete folate pools, while mycophenolate mofetil targets IMPDH to suppress lymphocyte proliferation. Beyond oncology and immunology, these pathways are also exploited in antimicrobial and antiviral drug development to target pathogen-specific metabolic requirements (Source: StatPearls). However, because these enzymes are also active in healthy rapidly-dividing cells, drugs targeting them often carry significant side effects such as bone marrow suppression and mucosal injury.

Other names

Nucleotide biosynthesis enzymesPurine metabolic enzymesDNA and RNA synthesis enzymesAntimetabolite targets

These enzymes are targeted by antimetabolites that act as structural analogs of natural nucleotides or as inhibitors of key biosynthetic steps, thereby depleting nucleotide pools, disrupting DNA and RNA synthesis, and inducing cell cycle arrest or apoptosis (Source: StatPearls, PubMed).