C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506-6045, USA.
J Biol Inorg Chem. 2011 Apr;16(4):633-9. doi: 10.1007/s00775-011-0767-x. Epub 2011 Mar 2.
Because interactions between cisplatin and plasma proteins contribute to drug efficacy and side effects, it is important to understand both the binding sites of cisplatin on the proteins and the formation of protein-cisplatin adducts. Previous results suggest that cisplatin preferentially binds to residues on the protein surface. The present work employed electrospray ionization mass spectrometry (MS) to identify such sites on both native and denatured ubiquitin (Ub). Fourier transform (FT) MS and tandem MS (MS/MS and MS(3)) enable analysis of Ub-cisplatin adduct digests to locate specific cisplatin binding sites. Results indicate that there are three such binding sites, i.e., M1, T12 and T14, and D32, on native Ub. The intensity of the relevant peaks in the FT-MS spectrum of the native Ub adduct digest demonstrates that residues T12 and T14 comprise the primary cisplatin binding site under the native conditions rather than residue M1 as reported in previous research studies. It is found in the present work, however, that M1 is the primary binding site on denatured Ub. Comparison of cisplatin binding sites on native and denatured Ub in this research demonstrates that the conformation of a protein significantly influences the preference of cisplatin for specific binding sites.
由于顺铂与血浆蛋白之间的相互作用会影响药物的疗效和副作用，因此了解顺铂在蛋白质上的结合部位以及形成的蛋白质-顺铂加合物非常重要。先前的研究结果表明，顺铂优先与蛋白质表面的残基结合。本工作采用电喷雾电离质谱（MS）鉴定天然和变性泛素（Ub）上的此类结合部位。傅里叶变换（FT）MS 和串联 MS（MS/MS 和 MS(3)）可用于分析 Ub-顺铂加合物的酶解产物，以确定特定的顺铂结合部位。结果表明，天然 Ub 上有三个这样的结合部位，即 M1、T12 和 T14 以及 D32。天然 Ub 加合物酶解产物的 FT-MS 谱中相关峰的强度表明，在天然条件下，T12 和 T14 残基构成了顺铂的主要结合部位，而不是先前研究报道的 M1 残基。然而，本工作发现 M1 是变性 Ub 的主要结合部位。本研究中天然和变性 Ub 上顺铂结合部位的比较表明，蛋白质的构象显著影响顺铂对特定结合部位的偏好。
