Metallocomplex-Peptide Interactions Studied by Ultrahigh Resolution Mass Spectrometry
Metallocomplex-Peptide Interactions Studied by Ultrahigh Resolution Mass Spectrometry
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DOI：
10.1021/jasms.9b00054
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发表时间：
2020-03-01
影响因子：
3.2
通讯作者：
O'Connor, Peter B.
中科院分区：
文献类型：
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作者：
Chiu, Cookson K. C.;Lam, Yuko P. Y.;O'Connor, Peter B.
Os-II芳烃抗癌配合物[（eta（6）-bip）Os（en）Cl]（+）（Osl-Cl;其中bip =联苯，en =乙二胺）与DNA（I）和生物分子强烈结合。本文采用高分辨傅立叶变换-离子回旋共振质谱（FT-ICR MS）研究了Osl-Cl与模型蛋白BSA的相互作用。利用碰撞活化解离（CAD）和电子捕获解离（ECD）研究了Osl在BSA上的特异性结合位置。CAD MS/MS被发现从金属-肽复合物中解离锇复合物，容易产生未修饰的片段并丢失位置信息。然而，ECD MS/MS在片段化后成功地保留了肽上的锇修饰，从而允许金属络合物结合的定位。这项研究表明，赖氨酸是一个可能的结合位置的Osl-Cl，除了在蛋氨酸，组氨酸和半胱氨酸的预期结合位点。使用纳米液相色谱（nLC）-FT-ICR ECD MS/MS研究，还揭示了多个结合位置，包括消化肽、谷氨酸和赖氨酸的N-末端和C-末端。这些结果显示了有机锇化合物的多靶向结合能力，并且可以用作更复杂系统的标准工作流程，例如，金属络合物细胞MS分析，以评估它们对常见生物分子的行为。
The Os-II arene anticancer complex [(eta(6)-bip)Os(en)Cl](+) (Osl-Cl; where bip = biphenyl and en = ethylenediamine) binds strongly to DNA(I) and biomolecules. Here we investigate the interaction between Osl-Cl and the model protein, BSA, using ultrahigh resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). The specific binding location of Osl on BSA was investigated with the use of collisionally activated dissociation (CAD) and electron capture dissociation (ECD). CAD MS/MS was found to dissociate the osmium complex from the metallo-peptide complex readily producing unmodified fragments and losing location information. ECD MS/MS, however, successfully retains the osmium modification on the peptides upon fragmentation allowing localization of metallocomplex binding. This study reveals that lysine is a possible binding location for Osl-Cl, apart from the expected binding sites at methionine, histidine, and cysteine. Using a nano liquid chromatography (nLC)-FT-ICR ECD MS/MS study, multiple binding locations, including the N-terminus and C-terminus of digested peptides, glutamic acid, and lysine were also revealed. These results show the multitargeting binding ability of the organo-osmium compound and can be used as a standard workflow for more complex systems, e.g., metallocomplex cell MS analysis, to evaluate their behavior toward commonly encountered biomolecules.