INVESTIGATION OF THE GAS-PHASE STRUCTURE OF ELECTROSPRAYED PROTEINS USING ION-MOLECULE REACTIONS
INVESTIGATION OF THE GAS-PHASE STRUCTURE OF ELECTROSPRAYED PROTEINS USING ION-MOLECULE REACTIONS
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DOI：
10.1016/1044-0305(94)85011-9
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发表时间：
1994-04-01
影响因子：
3.2
通讯作者：
SMITH, RD
中科院分区：
文献类型：
--
作者：
LOO, RRO;SMITH, RD
研究了氨、二甲胺、二乙胺和三甲胺与电喷雾电离（ESI）产生的多质子化蛋白质的质子转移反应，以探讨溶液和气相蛋白质结构之间的关系以及与离子-分子反应性的关系。离子-分子反应在基于ESI接口的大气压毛细管入口/反应器中进行到四极杆质谱仪。探索了两种类型的系统：（1）具有半胱氨酸二硫键的蛋白质和类似的二硫键还原的蛋白质，和（2）从溶液组合物喷雾的蛋白质，其中蛋白质具有不同的构象。虽然在这些条件下，半胱氨酸-半胱氨酸二硫键结合的蛋白质比等电荷的二硫键还原的蛋白质更具反应性，但对于由不同溶液构象产生的离子，没有注意到显著的反应性差异。还探讨了入口/反应器温度对有和没有胺试剂的电荷分布的影响，表明蛋白质的热变性可以发生在加热的毛细管入口。结果进行了讨论的背景下，最近的结果表明至少有一些高阶蛋白质结构的气相中的持久性。
Proton tranfer reactions of ammonia, dimethylamine, diethylamine, and trimethylamine with multiply protonated proteins generated by electrospray ionization (ESI) were examined to probe the relationship between solution and gas-phase protein structure and the relationship with ion-molecule reactivity. The ion-molecule reactions were carried out in an atmospheric pressure capillary inlet/reactor based upon an ESI interface to a quadrupole mass spectrometer. Two types of systems were explored: (1) proteins possessing cysteinecysteine disulfide bonds and the analogous disulfide-reduced proteins, and (2) proteins sprayed from solution compositions where the protein has different conformations. While the cysteine-cysteine disulfide-bound proteins were more reactive than equally charged disulfide-reduced proteins under these conditions, no significant reactivity differences were noted for ions arising from different solution conformations. The effect of inlet/reactor temperature on charge distributions with and without amine reagent was also explored, demonstrating that thermal denaturation of proteins can occur in heated capillary inlets. The results are discussed in the context of recent results indicating the presistence of at least some higher order protein structure in the gas phase.