Milosavljević A R, Rousseau P, Domaracka A, Huber B A, Giuliani A
Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, B.P. 48, 91192 Gif-sur-Yvette, France.
Phys Chem Chem Phys. 2017 Aug 2;19(30):19691-19698. doi: 10.1039/c7cp02075a.
Collisions of 375 keV Xe ions with trapped mass/charge selected poly-anions of the cytochrome C protein (∼12.5 kDa) were studied by coupling a linear quadrupole ion trap with low-energy ion beam facility. Tandem mass spectra were recorded for the protein precursor charge states ranging from -9 to -17. The present work reports the first study of slow highly charged ion collisions with poly-anions. A high signal to noise ratio allowed the study of the intensity of single and multiple electron removal by a projectile, as well as associated neutral losses, as a function of the target charge state. Relative single and double electron detachment cross sections were found to increase with increasing charge state of the precursor anion. The experimental findings are supported by the calculations of the total electron capture cross sections, based on the classical over-the-barrier model, restricted to a simple uniformly charged linear protein structure and a near-end electron capture.
通过将线性四极离子阱与低能离子束装置相结合，研究了375 keV的氙离子与捕获的细胞色素C蛋白（约12.5 kDa）的质量/电荷选择的多阴离子之间的碰撞。记录了蛋白质前体电荷态从-9到-17的串联质谱。本工作报道了首次对慢的高电荷离子与多阴离子碰撞的研究。高信噪比使得能够研究作为目标电荷态函数的单次和多次电子被射弹移除的强度以及相关的中性损失。发现相对单次和双次电子脱离截面随着前体阴离子电荷态的增加而增加。基于经典的势垒模型，限于简单的均匀带电线性蛋白质结构和近端电子捕获，对总电子俘获截面的计算支持了实验结果。
