Refining solutions acid derivatives

Sulfur Compounds Present in Refining Solutions. Acid and alkaline derivatives are discussed separately. 

The only reported structure for a copper metallothionein, also unique for an Ag-substituted derivative, is for yeast S. cerevisae), which includes 12 Cys and 1 His out of the 53 amino acid residues. The NMR solution structure of both forms allowed determination of the backbone fold for the first 40 residues of the protein. In addition, based on the fact that only seven major Ag resonances were observed for the reconstituted protein, the Ag-to-Cys connectivities were derived and assumed identical for Cu-MT. Overall, it was concluded that yeast binds seven Cu or Ag ions in a single cluster, using 10 out of the 12 available Cys residues.A recent NMR reinvestigation of CU7-MT from the same species has shown that a number of different arrangements of the seven copper ions is consistent with the highly refined structure of the polypeptide fold. This, together with the different coordination preferences of Cu and Ag with thiolate sulfur ligands (see below), casts doubt on the isostructurality of both metalloforms in yeast MT. ... 

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