DNA polymerase, RNA polymerase and exonuclease activities on a DNA sequence modified by benzo[a]pyrene diolepoxide.
DNA polymerase, RNA polymerase and exonuclease activities on a DNA sequence modified by benzo[a]pyrene diolepoxide.
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DNA 聚合酶、RNA 聚合酶和核酸外切酶对苯并[a]芘二烯环氧丙烷修饰的 DNA 序列的活性。
DOI：
10.1093/carcin/13.9.1529
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发表时间：
1992
期刊：
影响因子：
4.7
通讯作者：
Springer,DL
中科院分区：
文献类型：
--
作者：
Thrall,BD;Mann,DB;Smerdon,MJ;Springer,DL
用苯并[α]芘二环氧化物修饰脱氧核糖核酸所产生的加合物对脱氧核糖核酸和核糖核酸的合成都有抑制作用。这一现象已被用作确定致癌物结合在已定义DNA序列中的分布的一种方法。由于不同的酶处理加合物DNA的方式可能不同，因此需要对加合物DNA上的不同酶活性进行关键的比较。因此，在单碱基分辨率下，我们比较了DNA聚合酶活性块与RNA聚合酶和核酸外切酶的活性。BPDE加合物以剂量依赖的方式阻断克隆的T7DNA聚合酶(Sequenase)的进程。虽然大多数这些片段在加成鸟嘌呤之前位于一个碱基上，但我们也观察到一些与特定鸟嘌呤相反的片段，这表明在某些序列中，聚合酶插入了与修饰的鸟嘌呤相反的碱基。用T4DNA聚合酶(3‘-→-5’)也能抑制DNA的核酸外切酶活性；但是，T4核酸外切酶的片段比相应的鸟嘌呤多迁移两个或多个碱基。使用Sequenase和T4核酸外切酶对加合物分布的作图得到了类似的结果，表明长链的鸟嘌呤被优先修饰，并且在多聚鸟嘌呤序列中，5‘鸟嘌呤比3’鸟嘌呤被更严重地修饰。SP6RNA聚合酶对加合物DNA的转录也呈剂量依赖性抑制。然而，对DNA聚合酶构成强阻挡的加合碱基并不总是对RNA聚合酶构成强阻挡。因此，在加合物分布方面，Sequenase和T4核酸外切酶提供的结果比RNA聚合酶更一致，因为RNA聚合酶的阻断与鸟嘌呤的相关性较差。
Adducts produced by modification of DNA with benzo-[α]pyrene diolepoxide (BPDE) are known to inhibit both DNA and RNA synthesis. This phenomenon has been used as a method for determining the distribution of carcinogen binding within defined DNA sequences. A critical comparison of different enzyme activities on adducted DNA is needed, since different enzymes may process adducted DNA differently. Thus, we compared blocks in DNA polymerase activity with that of an RNA polymerase and with an exonuclease at single base resolution. BPDE adducts blocked the progression of cloned T7 DNA polymerase (Sequenase) in a dose-dependent manner. Although the majority of these blocks were at one base prior to adducted guanines, we also observed some blocks opposite specific guanines, suggesting that in some sequences the polymerase inserted a base opposite the modified guanine. Digestion with T4 DNA polymerase (3′ → 5′) exonuclease activity was also blocked in BPDE-adducted DNA; however, fragments produced by blocks in T4 exonuclease migrated two or more bases longer than the corresponding guanine. Mapping of adduct distributions using both Sequenase and T4 exonuclease gave similar results, demonstrating that a long tract of guanines was preferentially modified, and within a polyguanine sequence, the 5′ guanines were more heavily modified than the 3′ guanines. Transcription of adducted DNA by SP6 RNA polymerase was also inhibited in a dose-dependent manner. However, adducted bases which posed strong blocks to the DNA polymerase were not always strong blocks to the RNA polymerase. Thus, in terms of adduct distribution, Sequenase and T4 exonuclease provided more consistent results than the RNA polymerase, since blockage of the RNA polymerase correlated poorly with guanines.
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源自人中性粒细胞的血小板激活因子的结构阐明。
DOI：
10.1016/0006-291x(84)90751-4
发表时间：
1984
影响因子：
3.1
作者：
Clay,KL;Murphy,RC;Andres,JL;Lynch,J;Henson,PM
通讯作者：
Henson,PM
影响因子：
--
作者：
FINDLAY, SR;LICHTENSTEIN, LM;PINCKARD, RN
通讯作者：
PINCKARD, RN
选择离子监测在血小板活化因子测定中的应用。
DOI：
--
发表时间：
1983
期刊：
Journal of Biochemistry (Tokyo)
影响因子：
--
作者：
K. Satouchi;M. Oda;K. Yasunaga;K. Saito
通讯作者：
K. Saito
离体灌注大鼠肺中血小板激活因子的代谢。
DOI：
10.1172/jci113028
发表时间：
1987
期刊：
The Journal of clinical investigation
影响因子：
--
作者：
Haroldsen,PE;Voelkel,NF;Henson,JE;Henson,PM;Murphy,RC
通讯作者：
Murphy,RC
通过气相色谱/负离子化学电离质谱法测量亚皮克量的血小板活化因子 (AGEPC)。
DOI：
--
发表时间：
1986
期刊：
Biomedical & environmental mass spectrometry
影响因子：
--
作者：
C. Ramesha;Walter C. Pickett
通讯作者：
Walter C. Pickett