Mashaly RI, Habib SL, Salem MH, el Deeb SA, Safwat MM, Sarhan F. In vitro effect of aflatoxin B1 on the transcriptional activity of DNA template, chromatin and soluble DNA-dependent RNA polymerases in buffalo liver.
Toxicol Lett 1988;
41:69-75. [PMID:
3128897 DOI:
10.1016/0378-4274(88)90009-4]
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Abstract
The effect of aflatoxin B1 on the DNA template and DNA-dependent RNA polymerases in buffalo liver was studied. Aflatoxin B1 inhibited both Mg2+- and Mn2+-activated RNA polymerases in a dose-dependent manner. At 10 micrograms the inhibition of both enzymes was almost complete. The inhibitory effect on the solubilized enzymes was higher than the chromatin-bound, suggesting a direct effect at the enzyme level. On the other hand, incubating DNA or deoxyribonucleoprotein (DNP) with 2 micrograms aflatoxin reduces its transcriptional capacity with a greater effect on the Mg2+-activated RNA polymerase than the Mn2+-activated enzyme. These results suggest that aflatoxin B1 inhibits in vitro transcription in buffalo liver at both enzyme and template levels.
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