SELECTIVE DISPLACEMENT OF NUCLEAR PROTEINS BY ANTITUMOR DRUGS HAVING AFFINITY FOR NUCLEIC-ACIDS
SELECTIVE DISPLACEMENT OF NUCLEAR PROTEINS BY ANTITUMOR DRUGS HAVING AFFINITY FOR NUCLEIC-ACIDS
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DOI：
10.1073/pnas.86.13.5151
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发表时间：
1989-07-01
影响因子：
11.1
通讯作者：
DARZYNKIEWICZ, Z
中科院分区：
文献类型：
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作者：
BARTKOWIAK, J;KAPUSCINSKI, J;DARZYNKIEWICZ, Z
在低离子强度缓冲液（10 mM NaCl）中存在和不存在这些药物的情况下，通过对大鼠肝细胞核释放的蛋白质进行聚丙烯酰胺凝胶电泳，研究了抗肿瘤药物米托蒽醌、阿米坦酮、阿霉素、光神霉素和放线菌素 D 以及嵌入配体乙锭的核染色质结合位点。在25-50μM游离配体浓度下，每种药物通过(i)释放新蛋白质，(ii)改变特定提取蛋白质的数量，和/或(iii)选择性捕获细胞核中的其他蛋白质，产生不同分子量的可提取蛋白质的特定且可重复模式。高达100μM的乙锭不影响蛋白质从细胞核中的释放。这些结果表明，每个配体要么在染色质中具有不同的结合位点，要么通过改变不同组蛋白质对其各自结合位点的亲和力以特定方式调节染色质结构，从而选择性提取或捕获它们。乙锭没有作用表明配体插入 DNA 本身不会改变核蛋白的释放。如果发现抗肿瘤药物选择性释放或保留的核蛋白模式与生物活性相关，那么这种类型的分析可能有助于新药设计和筛选。
The nuclear chromatin binding sites of the antitumor drugs mitoxantrone, ametantrone, doxorubicin, mithramycin, and actinomycin D and the intercalating ligand ethidium were studied by polyacrylamide gel electrophoresis of the proteins released from rat liver nuclei in the presence and absence of these drugs in buffer in low ionic strength (10 mM NaCl). At 25-50 .mu.M free ligand concentration, each drug produced a specific and reproducible pattern of extractable proteins of different molecular weight by (i) releasing new proteins, (ii) altering the quantity of particular extracted proteins, and/or (iii) selectively entrapping other proteins in the nuclei. Ethidium, up to 100 .mu.M, did not affect release of proteins from the nuclei. These results indicate that each ligand either has different binding site(s) in chromatin or modulates chromatin structure in a specific way by changing the affinity of different sets of proteins for their respective binding sites, resulting in their selective extraction or entrapment. The lack of effect of ethidium indicates that intercalation of the ligand to DNA, per se, does not alter the release of nuclear proteins. If patterns of nuclear proteins selectively released or retained by antitumor drugs are found to correlate with biological activity, this type of analysis may be helpful in new drug design and screening.