The interaction of the mixed-metal complex trans-[(MeH2N)2Pt(mcyt)2PdCl]NO3 (mcyt = 1-methyl-cytosinate) with various derivatives of amino acids mimicking the side-chain metal binding sites of proteins were studied by 1H NMR, spectrophotometric and potentiometric methods. The derivatives included N-acetylamino acids (N-acetyl-methionine, -cysteine, -lysine, -histidine and -histamine), amino acids (glycine and methionine) and dipeptides (Gly-Met and Gly-Lys). The coordination of independent thioether, amino or imidazole nitrogen side-chain donor groups resulted in the formation of stable mono- or di-nuclear adducts. The formation of dinuclear complexes was characteristic of dipeptides and N-acetyl-histidine and -histamine. The existence of linkage isomers was demonstrated in the latter case, the Pd-N(3) (imidazole) isomers being more favoured. The possibility of stable chelate formation with palladium(II) (e.g. S,O for N-acetylcysteine and S, N for methionine) significantly enhanced the decomposition of the mixed-metal complex, leading to trans-[Pt(NH2Me)2(Hmcyt)2]2+.
|Number of pages||6|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 1995|
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