Exploring the Effects of Methylation on the CID of Protonated Lysine: A Combined Experimental and Computational Approach
Exploring the Effects of Methylation on the CID of Protonated Lysine: A Combined Experimental and Computational Approach
复制标题
探索甲基化对质子化赖氨酸 CID 的影响：实验和计算相结合的方法
DOI：
10.1021/jasms.1c00225
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发表时间：
2021
影响因子：
3.2
通讯作者：
Barnes, George L.
中科院分区：
文献类型：
--
作者：
Lucas, Kenneth;Chen, Amy;Schubmehl, Megan;Kolonko, Kristopher J.;Barnes, George L.
我们报道了实验、模拟和密度泛函理论计算的结果，重点描述了1-赖氨酸-H+及其侧链甲基化类似物Nε-甲基-1-赖氨酸-H+（Me 1-lysine-H+）、Nε，Nε-二甲基-1-赖氨酸-H+（Me 2-lysine-H+）和N ε，N ε，Nε-三甲基-1-赖氨酸-H+（Me 3-lysine-H+）的碰撞诱导解离反应动力学。在实验测量中观察到的主要途径是m/z 130和84，前者在低碰撞能量下占主导地位，后者在中高碰撞能量下占主导地位。Them/z130峰对应于N（CH 3）nH3-n的损失，而Them/z 84具有可能以H2O + CO形式的H2 CO2的额外损失。在直接动力学模拟的时间范围内，m/z130和101是最多的峰，后者被确定为中间tom/z 84。模拟允许确定导致这些产物的几种反应途径。图论分析能够阐明组成每个峰的重要结构。甲基化导致侧链酰胺基团的优先损失和模拟中它们/z 84峰群内的环状结构的减少。
We report the results of experiments, simulations, and DFT calculations that focus on describing the reaction dynamics observed within the collision-induced dissociation ofl-lysine-H+and its side-chain methylated analogues,Nε-methyl-l-lysine-H+(Me1-lysine-H+),Nε,Nε-dimethyl-l-lysine-H+(Me2-lysine-H+), andNε,Nε,Nε-trimethyl-l-lysine-H+(Me3-lysine-H+). The major pathways observed in the experimental measurements werem/z130 and 84, with the former dominant at low collision energies and the latter at intermediate to high collision energies. Them/z130 peak corresponds to loss of N(CH3)nH3–n, whilem/z84 has the additional loss of H2CO2likely in the form of H2O + CO. Within the time frame of the direct dynamics simulations,m/z130 and 101 were the most populous peaks, with the latter identified as an intermediate tom/z84. The simulations allowed for the determination of several reaction pathways that result in these products. A graph theory analysis enabled the elucidation of the significant structures that compose each peak. Methylation results in the preferential loss of the side-chain amide group and a reduction of cyclic structures within them/z84 peak population in simulations.