Carboxyflavins, novel inhibitors of Taq DNA polymerase

Carboxyflavins were found to be potent selective inhibitors of Tag DNA polymerase in a polymerase chain reaction. The inhibitions were dose-dependent, and complete inhibitions were observed at the concentration of 3.0 mu M Carboxyflavins were much less, or not sensitive to the DNA polymerases tested such as calf thymus DNA polymerase alpha, rat DNA polymerase beta, human immunodeficiency virus type 1 reverse transcriptase, the Klenow Fragment of E. coli DNA polymerase I and T4 DNA polymerase. To our knowledge, there is no other report of an agent that selectively inhibits only a thermophilic polymerase. Interestingly, the carboxy-flavins were able to prevent DNA synthesis in the murine lymphoid leukemia cell line L1210 in vitro; almost complete inhibitory levels were achieved in the range of less than 10 mu M.