- Formation of peptide disulfide bonds through a trans-dibromido-Pt(IV) complex oxidation reaction: Kinetic and mechanistic analyses
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A trans-dibromido-Pt(IV) complex [PtBr2(en)2]Br2 was synthesized and evaluated for the synthesis of peptide disulfide bonds in this work. The reactions between the Pt(IV) complex and dicysteine-containing peptides were carried out in various aqueous solutions. As a result, excellent yields with fast reaction rates were achieved. Methionine residue was intact when the Pt(IV) complex reacted with a dicysteine and methionine-containing peptide. 3,6-Dioxa-1,8-octanedithiol (DODT) was selected as a model compound of the dicysteine-containing peptide. Kinetic studies for the reaction between the Pt(IV) complex and DODT were performed in different pH solutions. It is first-order both in [Pt(IV)] and in [DODT]. A reaction mechanism was proposed accordingly. The kinetic and mechanistic results demonstrated that the reaction rate for the formation of peptide disulfide bond via the Pt(IV) oxidation is increased with the increase of pH of the reaction medium. The protolytic constants of the two thiol groups in peptide also play a critical role in reaction rate. On the other hand, kinetic studies demonstrated that the Pt(IV) complex trans-[PtBr2(en)2]2+ can be used in an acidic medium for the purpose of synthesis of disulfide bonds.
- Ma, Dongying,Song, Changying,Sun, Jingjing,Shen, Shigang,Huo, Shuying
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- Construction of disulfide bonds in peptides via immobilized platinum(IV) complex oxidation
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A novel TentaGel resin supported platinum(IV) complex named TentaGel-Pt(IV) was synthesized and characterized by SEM, XPS, ICP-MS and UV–vis spectrophotometry. The formation of intramolecular disulfides in eleven dithiol-containing peptides of variable lengths using TentaGel-Pt(IV) was investigated at room temperature. The disulfide-containing peptides were formed in excellent oxidation yields and were easily separated by filtration upon completion of the reaction. Excellent reusability of TentaGel-Pt(IV) was also achieved. The mechanism for construction of the disulfide bond in peptides via TentaGel-Pt(IV) oxidation was proposed.
- Sun, Jingjing,Zhang, Yamei,Huo, Shuying,Shen, Shigang
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supporting information
(2019/12/24)
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- A study to develop platinum(iv) complex chemistry for peptide disulfide bond formation
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Platinum(iv) complexes with a heterocyclic ligand and an ancillary ligand have been investigated and applied for treating various tumour cell lines. Another application of the Pt(iv) complexes in forming peptide disulfide bonds was investigated in this work. For development of Pt(iv) complex chemistry for disulfide bond formation in peptides, two Pt(iv) complexes, [PtCl2(phen)(en)]Cl2 and [PtCl2(bpy)(en)]Cl2, were synthesized and characterized using elemental analysis, ESI-MS and NMR. Subsequently, they were investigated as oxidants for the formation of disulfide bonds in various peptides. Excellent purities and yields of disulfide-containing peptides were achieved when the reactions were carried out in aqueous solution. The reactions were completed rapidly in a wide range of pH values even in acidic medium at room temperature. An intramolecular disulfide bond was formed in each of the peptides in a solution containing two dithiol-containing peptides, making the Pt(iv) complexes useful for generating disulfide-containing peptide libraries. In addition, the two Pt(iv) complexes can be used as oxidants for the synthesis of disulfide bonds on a resin, which is a more convenient method to synthesize disulfide-containing peptides through automation.
- Huo, Shuying,Shen, Shigang,Song, Changying,Sun, Jingjing,Zhao, Xiaowei
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supporting information
p. 1736 - 1741
(2020/02/20)
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