Interaction of cisplatin in activated diaqua-form with His-Met dipeptide is explored using DFT approach with PCM model. First the conformation space of the dipeptide is explored to find the most stable structure (labeled 0683). Several functionals with double-zeta basis set are used for optimization and obtained order of conformers is confirmed by the CCSD(T) single-point calculations. Supermolecular model is used to determine reaction coordinate for the replacement of aqua ligands consequently by N-site of histidine and S-site of methionine and reversely. Despite the monoadduct of Pt-S(Met) is thermodynamically less stable this reaction passes substantially faster (by several orders of magnitude) than coordination of cisplatin to histidine. The consequent chelate formation occurs relatively fast with energy release up to 12 kcal mol-1.

• Keywords
• Anticancer drug, Computational chemistry, Density functional theory, Heavy metal, Thermodynamics,
• MeSH
• Chelating Agents chemistry   MeSH
• Cisplatin chemistry   MeSH
• Dipeptides chemistry   MeSH
• Histidine chemistry   MeSH
• Kinetics MeSH
• Methionine chemistry   MeSH
• Antineoplastic Agents chemistry   MeSH
• Density Functional Theory * MeSH
• Thermodynamics MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Chelating Agents MeSH
• Cisplatin MeSH
• Dipeptides MeSH
• Histidine MeSH
• Methionine MeSH
• Antineoplastic Agents MeSH

Hydration reactions of two anticancer Pt(IV) complexes JM149 and JM216 (Satraplatin) were studied computationally together with the hydration of the Pt(II) complex JM118, which is a product of the Satraplatin reduction. Thermodynamic and kinetic parameters of the reactions were determined at the B3LYP/6-311++G(2df.2pd)//B3LYP/6-31 + G(d)) level of theory. The water solution was modeled using the COSMO implicit solvation model, with cavities constructed using Klamt's atomic radii. It was found that hydration of the Pt(IV) complexes is an endergonic/endothermic reaction. It follows the (pseudo)associative mechanism is substantially slower (k ≈ 10(-11) s(-1)) than the corresponding reaction of Pt(II) analogues ((k ≈ 10(-5) s(-1)). Such a low value of the reaction constant signifies that the hydration of JM149 and Satraplatin is with high probability a kinetically forbidden reaction. Similarly to JM149 and Satraplatin, the hydration of JM118 is an endothermic/endoergic reaction. On the other hand, the kinetic parameters are similar to those of cisplatin Zimmermann et al. (J Mol Model 17:2385-2393, 2011), allowing the hydration reaction to occur at physiological conditions. These results suggest that in order to become active Satraplatin has to be first reduced to JM118, which may be subsequently hydrated to yield the active species.

• MeSH
• Models, Chemical MeSH
• Kinetics MeSH
• Quantum Theory MeSH
• Ligands MeSH
• Models, Molecular MeSH
• Organoplatinum Compounds chemistry   MeSH
• Oxidation-Reduction MeSH
• Antineoplastic Agents chemistry   MeSH
• Thermodynamics MeSH
• Water chemistry   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• amminedichloro(cyclohexylamine)platinum(II) MeSH Browser
• JM 335 MeSH Browser
• Ligands MeSH
• Organoplatinum Compounds MeSH
• Antineoplastic Agents MeSH
• satraplatin MeSH Browser
• Water MeSH