Parr Carol, Pierce Sarah E, Smith Suncerae I, Brodbelt Jennifer S
Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712.
Int J Mass Spectrom. 2011 Jul 1;304(2-3):115-123. doi: 10.1016/j.ijms.2010.06.007.
The reactions of two well-known chemical probes, glyoxal and potassium permanganate (KMnO(4)), with oligodeoxynucleotides were monitored by electrospray ionization (ESI) mass spectrometry to evaluate the influence of the sequence of DNA, its secondary structure, and interactions with associated ligands on the reactivity of the two probes. Glyoxal, a guanine-reactive probe, incorporated a mass shift of 58 Da, and potassium permanganate (KMnO(4)) is a thymine-reactive probe that resulted in a mass shift of 34 Da. The reactions depended on the accessibility of the nucleobases, and the peak abundances of the adducts in the ESI-mass spectra were used to quantify the extent of the chemical probe reactions. In this study, both mixed-base sequences were studied as well as control sequences in which one reactive site was located at the terminus or center of the oligodeoxynucleotide while the surrounding bases were a second, different nucleobase. In addition, the reactions of the chemical probes with non-covalent complexes formed between DNA and either actinomycin D or ethidium bromide, both known to interact with single strand DNA, were evaluated.
通过电喷雾电离（ESI）质谱监测了两种著名化学探针乙二醛和高锰酸钾（KMnO₄）与寡脱氧核苷酸的反应，以评估DNA序列、其二级结构以及与相关配体的相互作用对这两种探针反应活性的影响。乙二醛是一种与鸟嘌呤反应的探针，会产生58 Da的质量位移，而高锰酸钾（KMnO₄）是一种与胸腺嘧啶反应的探针，会导致34 Da的质量位移。这些反应取决于核碱基的可及性，ESI质谱中加合物的峰丰度用于量化化学探针反应的程度。在本研究中，研究了混合碱基序列以及对照序列，在对照序列中，一个反应位点位于寡脱氧核苷酸的末端或中心，而周围的碱基是另一种不同的核碱基。此外，还评估了化学探针与DNA和放线菌素D或溴化乙锭之间形成的非共价复合物的反应，这两种物质都已知与单链DNA相互作用。
