Tsai M J, Saunders G F
Proc Natl Acad Sci U S A. 1973 Jul;70(7):2072-6. doi: 10.1073/pnas.70.7.2072.
The mechanism of inhibition of human RNA polymerase by four rifamycin derivatives was investigated. Derivative AF/013 (3-formyl rifamycin SV:O-n-octyloxime) with strong hydrophobic side chains prevents the polymerase from binding to DNA and also affects the size of RNA synthesized. Derivative PR/19 (3'-acetyl-1'-benzyl-2'-methylpyrrolo[3,2-c]-4-desoxy-rifamycin SV) only affects RNA synthesis when RNA polymerase has been previously incubated with the drug or when the reaction was performed at high salt concentration [0.14 M (NH(4))(2)-SO(4)]. Our results suggest that these drugs exert their inhibitory actions by binding to the enzyme instead of DNA.
研究了四种利福霉素衍生物对人RNA聚合酶的抑制机制。具有强疏水侧链的衍生物AF/013(3-甲酰基利福霉素SV:O-正辛基肟)可阻止聚合酶与DNA结合,并且还会影响合成的RNA的大小。衍生物PR/19(3'-乙酰基-1'-苄基-2'-甲基吡咯并[3,2-c]-4-脱氧-利福霉素SV)仅在RNA聚合酶预先与该药物孵育时或在高盐浓度[0.14 M硫酸铵]下进行反应时才影响RNA合成。我们的结果表明,这些药物通过与酶而非DNA结合来发挥其抑制作用。