Identifying the interactions of small molecules with biomolecules in complex cellular environments is a significant challenge. As one important example, despite being widely used for decades, much is still not understood regarding the cellular targets of Pt(II)-based anticancer drugs. In this study we introduce a novel method for isolation of Pt(II)-bound biomolecules using a DNA hybridization pull-down approach. Using a modified Pt reagent, click-ligation of a DNA oligonucleotide to both a Pt(II)-bound DNA hairpin and bovine serum albumin (BSA) are demonstrated. Subsequent hybridization to a biotin-labeled oligonucleotide allows for efficient isolation of Pt(II)-bound species by streptavidin pulldown. We also find that platinated bovine serum albumin readily crosslinks to DNA in the absence of click ligation, and that a fraction of BSA-bound Pt(II) can transfer to DNA over time. Interestingly, in in vitro studies, fragmented mammalian DNA that is crosslinked to BSA through Pt(II) exhibits significantly increased protection from degradation by serum nucleases.

识别复杂细胞环境中小分子与生物分子的相互作用是一项重大挑战。作为一个重要的例子，尽管铂（II）基抗癌药物已广泛使用数十年，但人们对其细胞靶点仍知之甚少。在本研究中，我们介绍了一种使用 DNA 杂交 Pull-down 方法分离 Pt(II) 结合生物分子的新方法。使用改良的 Pt 试剂，证明了 DNA 寡核苷酸与 Pt(II) 结合的 DNA 发夹和牛血清白蛋白 (BSA) 的点击连接。随后与生物素标记的寡核苷酸杂交，可以通过链霉亲和素下拉有效分离 Pt(II) 结合的物质。我们还发现，在没有点击连接的情况下，铂化牛血清白蛋白很容易与 DNA 交联，并且随着时间的推移，一小部分 BSA 结合的 Pt(II) 可以转移到 DNA 上。有趣的是，在体外研究中，通过 Pt(II) 与 BSA 交联的哺乳动物 DNA 片段显示出显着增强的防止血清核酸酶降解的保护作用。