Comparison of collision- versus electron-induced dissociation of Pt(II) ternary complexes of histidine- and methionine-containing peptides
Comparison of collision- versus electron-induced dissociation of Pt(II) ternary complexes of histidine- and methionine-containing peptides
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DOI：
10.1002/rcm.4234
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发表时间：
2009-10-01
影响因子：
2
通讯作者：
O'Hair, Richard A. J.
中科院分区：
文献类型：
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作者：
Feketeova, Linda;Ryzhov, Victor;O'Hair, Richard A. J.
含有组氨酸的多肽(GH、HG、GGH、GHG、HGG)和含蛋氨酸的多肽(GM、MG、GGM、GMG、MGG)与铂配合物[铂(Terpy)Cl](+)(A)和[Pt(Dien)Cl](+)(B)孵育后，电喷雾电离得到了许多单电荷和双电荷的三元铂肽配合物，包括[铂(L)M](2+)和[铂(L)M-H](+)(其中L=配体或二烯；M是肽)。[铂(L)M](2+)配合物分别经历电子俘获解离、碰撞诱导解离和电子诱导解离，[铂(L)M-H](+)配合物分别经历电子俘获解离和电子诱导解离。ECD的结果表明，自由电子被金属离子俘获，从而削弱了与其配体的键。在配体terpy的情况下，它比dien更强地结合，这种减弱导致多肽的翻转。[Pt(Terpy)M](2+)络合物的ECD谱中的次要产物确实显示出沿着肽骨架的碎裂，但观察到的离子是a-、b-和y-型的。对于含蛋氨酸多肽的络合物，发现了一个标记离子[PT(L)SCH3](+)，它表明铂与蛋氨酸侧链结合。对于含有组氨酸的多肽，在许多情况下观察到一个含有铂、辅助配体和组氨酸亚胺的离子，从而表明组氨酸侧链与金属结合，但也发现其他铂配位方式(N-端)是竞争性的。这些发现与最近的一项发现是一致的(Sze等人。J.Biol.Inorg.化学。2009；14：163)在COPC蛋白中，铂占据了富含蛋氨酸的铜(I)结合部位，而不是富含组氨酸的铜(II)结合部位。版权所有(C)2009 John Wiley&Sons，Ltd.
Incubation of the histidine-containing peptides (GH, HG, GGH, GHG, HGG) and methionine-containing peptides (GM, MG, GGM, GMG, MGG) with the platinum complexes [Pt(terpy)Cl](+) (A) and [Pt(dien)Cl](+) (B) followed by electrospray ionisation (ESI) led to a number of singly and doubly charged ternary platinum peptide complexes, including [Pt(L)M](2+) and [Pt(L)M-H](+) (where L = the ligand terpy or dien; M is a peptide). Each of the [Pt(L)M](2+) complexes was subjected to electron capture dissociation (ECD), collision-induced dissociation (CID) and electron-induced dissociation (EID), while each of the [Pt(L)M-H](+) complexes was subjected to CID and EID. Results from ECD suggest that the free electron is captured by the metal ion thus weakening the bonds to its ligands. In the case of the ligand terpy, which binds more strongly than dien, this weakening leads to the toss of the peptide. The minor products in the ECD spectra of [Pt(terpy)M](2+) complexes do show fragmentation along the peptide backbone, but the ions observed are of the a-, b-, and y-type. For the complexes with methionine-containing peptides, a marker ion, [Pt(L)SCH3](+), was found which is indicative of binding of Pt to the methionine side chain. For the histidine-containing peptides, an ion containing platinum, the auxiliary ligand, and the histidine imine was observed in many instances, thus indicating the binding of the histidine side chain to the metal, but other modes of Pt coordination (N-terminus) were also found to be competitive. These findings are consistent with a recent finding (Sze et al. J. Biol. Inorg. Chem. 2009; 14: 163) that Pt occupies the methionine-rich copper(I)-binding site rather than histidine-rich copper(II)-binding site in the CopC protein. Copyright (C) 2009 John Wiley & Sons, Ltd.