氟罗沙星能潜在干扰Bloom解旋酶的DNA解链、ATP酶、DNA结合活性

Bloom (BLM) helicase plays an important role in the processes of DNA metabolism including DNA replication, repair, transcription, and recombination. Fleroxacin (FLRX), an important antibiotic applied in the empirical treatment of a variety of infections, has currently been used as the effective drugs for anti-cancer therapy. This study was conducted to determine the effects of FLRX on the biological properties of BLM helicase catalytic core by fluorescence polarization, spectroscopy, free-phosphorus assay, and gel retardation assay. Results indicated that the DNA unwinding and ATPase activities were inhibited by FLRX treatment. However, the DNA-binding activity was promoted. BLM-FLRX complex was form through one binding site, electrostatic force, and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was statically quenched by FLRX as a result of non-radioactive energy transfer. The results suggested that FLRX may affect the biological activities and conformation of the BLM helicase, which were beneficial to study the efficacy of DNA helicase as the target of drugs.