title: Fast cleavage of a diselenide induced by a platinum(II)-methionine complex and its biological implications.
abstract: Platinum-based anticancer drugs such as cisplatin induce increased oxidative stress and oxidative damage of DNA and other cellular components, while selenium plays an important role in the antioxidant defense system. In this study, the interaction between a platinum(II) methionine (Met) complex [Pt(Met)Cl(2)] and a diselenide compound selenocystine [(Sec)(2)] was studied by electrospray ionization mass spectrometry, high performance liquid chromatography mass spectrometry, and (1)H NMR spectroscopy. The results demonstrate that the diselenide bond in (Sec)(2) can readily and quickly be cleaved by the platinum complex. Formation of the selenocysteine (Sec) bridged dinuclear complex [Pt(2)(Met-S,N)(2)(μ-Sec-Se,Cl)](3+) and Sec chelated species [Pt(Met-S,N)(Sec-Se,N)](2+) was identified at neutral and acidic media, which seems to result from the intermediate [Pt(Met-S,N)(Sec-Se)Cl](+). An accelerated formation of S-Se and S-S bonds was also observed when (Sec)(2) reacted with excessive glutathione in the presence of [Pt(Met)Cl(2)]. These results imply that the mechanism of activity and toxicity of platinum drugs may be related to their fast reaction with seleno-containing biomolecules, and the chemoprotective property of selenium agents against cisplatin-induced toxicity could also be connected with such reactions.
authors: Applied Chemistry Department, Nanjing University of Finance and Economics, Nanjing 210003, PR China.
authors: Qin
authors: Q
authors: Liu
authors: Xiaoyong
authors: X
authors: Wang
authors: Xiaoliang
authors: X
authors: Yang
authors: Xiao
authors: X
authors: Liang
authors: Zijian
authors: Z
authors: Guo
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry; D000975:Antioxidants / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002945:Cisplatin / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D003553:Cystine / Q000031:analogs & derivatives* / Q000737:chemistry; D004249:DNA Damage; D004579:Electron Transport / Q000187:drug effects; D005978:Glutathione / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008715:Methionine / Q000737:chemistry*; D015394:Molecular Structure; D016566:Organoselenium Compounds / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects; D010984:Platinum / Q000737:chemistry*; D012643:Selenium / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D056831:Coordination Complexes; D016566:Organoselenium Compounds; C009226:selenocystine; D003553:Cystine; D010984:Platinum; D008715:Methionine; D005978:Glutathione; D012643:Selenium; D002945:Cisplatin