Wilmańska D, Szmigiero L, Gniazdowski M
Department of General Chemistry, Institute of Physiology and Biochemistry, School of Medicine, Lódź, Poland.
Z Naturforsch C J Biosci. 1989 Mar-Apr;44(3-4):307-11. doi: 10.1515/znc-1989-3-420.
In the presence of sulfhydryl compounds nitracrine, an anticancer drug, binds covalently to DNA. The accessibility of DNA in chromatin both to nitracrine and to 8-methoxypsoralen, which was used as a reference compound in this study, when assayed in NaCl concentrations from 0 to 2 M show similar characteristics. The initial decrease reaches a minimum at 0.15 M NaCl above which dissociation of non-histone proteins and histones at higher ionic strengths is demonstrated by an increase in accessible sites. The relative accessibility of DNA in chromatin to nitracrine is, however, lower than that found for 8-methoxypsoralen. Partial dissociation of chromatin with 0.7 M NaCl increases the accessibility of DNA in chromatin when assayed in the absence of NaCl but has no apparent influence when estimated at ionic strength close to physiological conditions.
在巯基化合物存在的情况下，抗癌药物硝吖啶会与DNA共价结合。当在0至2M的NaCl浓度下进行测定时，染色质中DNA对硝吖啶和8-甲氧基补骨脂素（本研究中用作参考化合物）的可及性表现出相似的特征。最初的下降在0.15M NaCl时达到最小值，高于此浓度时，较高离子强度下非组蛋白和组蛋白的解离通过可及位点的增加得以证明。然而，染色质中DNA对硝吖啶的相对可及性低于8-甲氧基补骨脂素。用0.7M NaCl对染色质进行部分解离，在无NaCl条件下测定时会增加染色质中DNA的可及性，但在接近生理条件的离子强度下估算时则没有明显影响。
