Inhibition of free DNA degradation by the deformation of DNA exposed to trace polycyclic aromatic hydrocarbon contaminants.
A rapid inhibitory effect of polycyclic aromatic hydrocarbons (PAHs) on DNA degradation was examined by conventional spectral analysis and microtitration. The purpose was to determine whether PAHs inhibited free DNA degradation by the enzyme DNase I. The results showed that model PAHs phenanthrene and pyrene combined with free DNA to decelerate DNA degradation by DNase I. Phenanthrene-induced inhibition was stronger than that of pyrene. Trace level of PAHs did not induce DNase I deactivation. The DNase I enzyme exhibited only slight shifts in IR absorption bands related to amide II and III upon PAH exposure, and no change was observed with other bands. The decelerating degradation of DNA is attributed to the changes in structure, backbone composition, and guanine constituents of DNA induced by PAHs inserted into double strands, and to the imidazole-like derivates from the combination of imidazole rings with pyrene.
Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Science, Nanjing Agricultural University, Nanjing 210095, PR China.
Fuxing
F
Kang
Yanzheng
Y
Gao
Qian
Q
Wang
D002274:Carcinogens, Environmental / Q000737:chemistry / Q000633:toxicity*; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D003850:Deoxyribonuclease I / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry / Q000633:toxicity*; D011721:Pyrenes / Q000737:chemistry / Q000633:toxicity*; D017550:Spectroscopy, Fourier Transform Infrared
D002274:Carcinogens, Environmental; D010616:Phenanthrenes; D011721:Pyrenes; C031181:phenanthrene; D004247:DNA; C030984:pyrene; D003850:Deoxyribonuclease I