MASS AND SEQUENCE VERIFICATION OF MODIFIED OLIGONUCLEOTIDES USING ELECTROSPRAY TANDEM MASS-SPECTROMETRY
MASS AND SEQUENCE VERIFICATION OF MODIFIED OLIGONUCLEOTIDES USING ELECTROSPRAY TANDEM MASS-SPECTROMETRY
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DOI：
10.1002/jms.1190300709
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发表时间：
1995-07-01
影响因子：
2.3
通讯作者：
LAW, SJ
中科院分区：
文献类型：
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作者：
BARRY, JP;VOUROS, P;LAW, SJ
电喷雾与串联质谱联用被证明在确定短修饰寡核苷酸的分子量和序列中具有实用性。三重去质子化分子前体的产物离子谱主要由通过两种碎裂途径形成的离子主导：第一，跨越5 ′ P-O磷酸键的断裂，第二，伴随核糖3 ′ C-O键断裂的非末端碱基的损失。如果这两种途径中的任一种是完整的，断裂发生在沿磷酸二酯骨架沿着的每个等同位置，或者，如果这两种途径都只是部分完成，则它们的互补性可用于更广泛的测序。修饰对核碱基的诱导作用显示影响后面的片段化过程。碱基修饰的电子亲和力越大，当分子被碰撞激活时，该碱基的损失就越容易。事实上，当核碱基含有高度感应吸移的取代基时，后一种碎片化支配产物离子谱。这种支配可以使得产物离子谱中存在很少的其他第一代碎片离子。然后，序列信息可能需要利用第二代产物离子。
Electrospray coupled with tandem mass spectrometry is shown to have utility in determining the molecular mass and the sequence of short modified oligonucleotides. The product ion spectrum of a triply deprotonated molecule precursor is dominated by ions formed via two fragmentation pathways: first, fragmentation across the 5'P-O phosphate bond, and second, loss of a non-terminal base with concomitant cleavage of the ribose 3'C-O bond, If either of these two pathways is complete with fragmentation occurring at each equivalent position along the phosphodiester backbone, then the oligomer may be sequenced, Alternatively, if both these pathways are only partially complete, their complementarity may be used for more extensive sequencing, The inductive effect of the modification on the nucleobase is shown to influence the latter fragmentation process, The greater the electron affinity of the base modification, the more facile is the loss of that base when the molecule is collisionally activated. In fact, this latter fragmentation dominates the product ion spectrum when a nucleobase contains a substituent that is highly inductively withdrawing, This domination can be such that few other first-generation fragment ions are present in the product ion spectrum, Sequence information may then require utilization of second-generation product ions.