[Interaction of proteins with platinum and palladium compounds with differing biological activities]

Protein interaction with bioactive platinum and palladium complex compounds was studied by solid-phase sorbent assay (SSA), turbidimetry, isoelectric focusing and circular dichroism. In SSA reaction ability of metal compounds can be represented as follows: [equation: see text] Reaction ability of proteins can be represented as follows: hemoglobin > serum albumin > immunoglobulin. The reaction products of serum albumin and metal compounds demonstrated more alkaline isoelectric points then the intact albumin resulting from adding positively charged metal centers [MeCl+, Me2+, [Me(H2O)n]2+, [Me(H2O)nCl]+ to albumin molecules. In metal-protein complexes circular dichroism demonstrated the diminution of alpha-helix structure percentage if compared with intact albumin, the most prominent effect being caused by K2[PdCl]4. The conformational distortion of albumin was significant. Metal compounds mostly affected the optical activity of S-S-protein bands (251-254 nm). Experimental evidence confirmed the hypothesis that platinum metal complexes with high reaction ability are less toxic than those with low reaction ability.