Infrared multiphoton dissociation of duplex DNA/drug complexes in a quadrupole ion trap.
Infrared multiphoton dissociation of duplex DNA/drug complexes in a quadrupole ion trap.
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四极离子阱中双链 DNA/药物复合物的红外多光子解离。
DOI：
10.1021/ac061946f
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发表时间：
2007
影响因子：
7.4
通讯作者：
Brodbelt,JenniferS
中科院分区：
文献类型：
--
作者：
Wilson,JeffreyJ;Brodbelt,JenniferS
用红外多光子解离(IRMPD)表征了三种不同GC含量的14碱基非自互补双链之一与八种不同DNA相互作用药物形成的非共价双链DNA/药物络合物，并与四极离子陷阱质谱仪中传统的碰撞激活解离(CAD)谱进行了比较。IRMPD得到了与以前报道的CAD结果类似的信息，在CAD结果中，对于含有更多AT富含序列和/或较小沟槽结合药物的络合物，链分离路径占主导地位，而对于含有插层药物和/或具有较高GC碱基含量的双链的络合物，药物喷射路径占主导地位。磷酸盐骨架在10.6μm处的大的光吸收截面促进了在短照射时间(<；2ms在50W)或使用较低的激光功率和较长的照射时间(<；15W在15ms)下的高效解离，激活时间与标准的CAD实验相当或更短。这种大的光吸收导致了一种可控的离子激活方法，该方法可以用来产生与CAD定性相似的光谱，同时最小化无信息的碱基损失解离路径，或者改为可调以产生高度的二次碎裂。此外，与常规CAD相关的低质量截止值在IRMPD中没有作用，导致低m/z区域的MS/MS信息更丰富。为了提高MS/MS的灵敏度，IRMPD也被用于多加成物的解离，并证明了一种两步IRMPD/IRMPD方法作为一种手段来提供特定的DNA序列信息，这些信息在筛选双链体混合物结合的药物时是有用的。
Noncovalent duplex DNA/drug complexes formed between one of three 14-base pair non-self-complementary duplexes with variable GC content and one of eight different DNA-interactive drugs are characterized by infrared multiphoton dissociation (IRMPD), and the resulting spectra are compared to conventional collisionally activated dissociation (CAD) mass spectra in a quadrupole ion trap mass spectrometer. IRMPD yielded comparable information to previously reported CAD results in which strand separation pathways dominate for complexes containing the more AT-rich sequences and/or minor groove binding drugs, whereas drug ejection pathways are prominent for complexes containing intercalating drugs and/or duplexes with higher GC base content. The large photoabsorptive cross section of the phosphate backbone at 10.6 μm promotes highly efficient dissociation within short irradiation times (<2 ms at 50 W) or using lower laser powers and longer irradiation times (<15 W at 15 ms), activation times on par with or shorter than standard CAD experiments. This large photoabsorptivity leads to a controllable ion activation method which can be used to produce qualitatively similar spectra to CAD while minimizing uninformative base loss dissociation pathways or instead be tuned to yield a high degree of secondary fragmentation. Additionally, the low-mass cutoff associated with conventional CAD plays no role in IRMPD, resulting in richer MS/MS information in the lowm/zregion. IRMPD is also used for multiadduct dissociation in order to increase MS/MS sensitivity, and a two-stage IRMPD/IRMPD method is demonstrated as a means to give specific DNA sequence information that would be useful when screening drug binding by mixtures of duplexes.