Purine biosynthetic pathway and DNA replication machinery

The target "Multiple enzymes in purine synthesis and replicating DNA" refers to a collective group of enzymes and metabolic processes essential for the production of purine nucleotides and the maintenance of genomic integrity. Key components include enzymes of the de novo purine synthesis pathway, such as amidophosphoribosyltransferase (GPAT) and inosine-5'-monophosphate dehydrogenase (IMPDH), as well as the DNA replication machinery including various DNA polymerases [1, 3, 4]. These enzymes work in concert to provide the adenine and guanine building blocks required for DNA and RNA synthesis, making them critical for cell proliferation and survival [1]. In clinical oncology and rheumatology, this pathway is targeted by antimetabolite drugs like 6-mercaptopurine and methotrexate, which act as fraudulent substrates or competitive inhibitors [2]. By disrupting nucleotide pools or incorporating directly into the DNA strand, these agents trigger cell cycle arrest and apoptosis in rapidly dividing cells [1, 2]. While highly effective in treating leukemias and autoimmune disorders, the non-specific nature of targeting these fundamental processes often results in significant toxicities, particularly myelosuppression and hepatotoxicity [2, 5]. Consequently, patient monitoring for genetic variants in metabolizing enzymes like TPMT is often required to mitigate safety risks [5].

Other names

Multiple enzymes in purine synthesis and replicating DNAPurine metabolismDe novo purine synthesis pathwayDNA synthesis machineryAntimetabolite targets

Inhibition of key enzymes in the purine biosynthetic pathway (such as GPAT and IMPDH) and/or the incorporation of antimetabolite analogues into DNA, leading to the inhibition of DNA synthesis and induction of apoptosis [1, 2].