DIRECT OBSERVATION OF A DNA QUADRUPLEX BY ELECTROSPRAY IONIZATION MASS-SPECTROMETRY
DIRECT OBSERVATION OF A DNA QUADRUPLEX BY ELECTROSPRAY IONIZATION MASS-SPECTROMETRY
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DOI：
10.1002/bms.1200220307
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发表时间：
1993-03-01
期刊：
影响因子：
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通讯作者：
SMITH, RD
中科院分区：
文献类型：
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作者：
GOODLETT, DR;CAMP, DG;SMITH, RD
在含有0.1 mM乙二胺四乙酸的10 mM磷酸钠（pH 7.6）中，通过负离子电喷雾电离（ESI）质谱法在低DeltaLe-skimmer（DELTANS）偏倚（-150 V）下检测到对应于非共价四链寡核苷酸d（CGCG 4GCG）4的离子，但在较高的DELTANS偏倚（> -250 V）下检测不到。相比之下，当样品脱盐并通过ESI质谱法在低DELTANS偏压下分析时，仅观察到单链d（CGCG 4GCG）物质的离子。这些数据与光谱学证据一致，光谱学证据显示具有序列基序5'd（CGCG（n）GCG）3 '（其中n = 2-5）的寡核苷酸在单原子阳离子如K+、Ca 2+、Na+和Li+存在下形成稳定的四链复合物，但在它们不存在下不形成。
In 10 mM sodium phosphate, pH 7.6, containing 0.1 mM ethylenediaminetetraacetic acid, ions corresponding to the non-covalent, four-stranded oligonucleotide, d(CGCG4GCG)4, were detected by negative ion electrospray ionization (ESI) mass spectrometry at a low nozzle-skimmer (DELTANS) bias (-150 V), but not at a higher DELTANS bias (> -250 V). In contrast, when the sample was desalted and analyzed by ESI mass spectrometry at a low DELTANS bias only ions for the single-stranded d(CGCG4GCG) species were observed. These data agree with spectroscopic evidence which showed that oligonucleotides with the sequence motif 5'd(CGCG(n)GCG)3', where n = 2-5, formed stable four-stranded complexes in the presence of monatomic cations, like K+, Ca2+, Na+ and Li+, but not in their absence.