Zn(2+) and Cd(2+) cationized serine complexes: infrared multiple photon dissociation spectroscopy and density functional theory investigations.
Zn(2+) and Cd(2+) cationized serine complexes: infrared multiple photon dissociation spectroscopy and density functional theory investigations.
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Zn(2 ) 和 Cd(2 ) 阳离子化丝氨酸配合物：红外多光子解离光谱和密度泛函理论研究。
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
P. Armentrout
中科院分区：
文献类型：
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作者：
R. A. Coates;G. C. Boles;Christopher P. McNary;G. Berden;J. Oomens;P. Armentrout
使用自由电子激光 FELIX 并结合从头计算，通过红外多光子解离 (IRMPD) 作用光谱研究了与丝氨酸 (Ser) 结合的锌和镉阳离子的气相结构。为了确定实验观察到的物质[Zn(Ser-H)CH3CN](+)和CdCl(+)(Ser)的结构，将测量的作用光谱与在B3LYP/6-311+G(d,p)水平计算的含Zn(2+)配合物的线性吸收光谱和含Cd(2+)配合物的B3LYP/def2-TZVP水平计算的线性吸收光谱进行比较。观察到的 IMPD 光谱与预测光谱之间的良好一致性允许识别存在的异构体。与氯化镉相互作用的完整氨基酸采用三齿螯合，涉及氨基酸主链胺和羰基以及侧链羟基[N,CO,OH]。去质子化的丝氨酸-锌络合物中观察到存在两个低能构象异构体，具有与镉络合物相同的三齿配位，但质子损失发生在羟基侧链 [N,CO,O(-)] 和氨基酸主链的羧酸 [N,CO(-),OH] 处。这些结果与先前获得的具有半胱氨酸的类似复合物的类似结果进行比较是有利的。
The gas-phase structures of zinc and cadmium dications bound to serine (Ser) are investigated by infrared multiple photon dissociation (IRMPD) action spectroscopy using the free electron laser FELIX, in combination with ab initio calculations. To identify the structures of the experimentally observed species, [Zn(Ser-H)CH3CN](+) and CdCl(+)(Ser), the measured action spectra are compared to linear absorption spectra calculated at the B3LYP/6-311+G(d,p) level for Zn(2+) containing complexes and B3LYP/def2-TZVP levels for Cd(2+) containing complexes. Good agreement between the observed IRMPD spectra and the predicted spectra allows identification of the isomers present. The intact amino acid interacting with cadmium chloride adopts a tridentate chelation involving the amino acid backbone amine and carbonyl groups as well as the hydroxyl group of the side-chain, [N,CO,OH]. The presence of two low-energy conformers is observed for the deprotonated serine-zinc complex, with the same tridentate coordination as for the cadmium complex but proton loss occurs at both the hydroxyl side-chain, [N,CO,O(-)], and the carboxylic acid of the amino acid backbone, [N,CO(-),OH]. These results are profitably compared with the analogous results previously obtained for comparable complexes with cysteine.