Peculiar features of the aggregation effect of silver(I) ion on hemoglobin

Inhibition of the Escherichia coli RecA protein: zinc(II), copper(II) and mercury(II) trap RecA as inactive aggregates

“…(2) Binding of transition metal ions to specific protein sidechains may disrupt RecAÕs normal core packing, allowing the aggregation of partially unfolded monomers. Salts of Cu(II), Hg(II) or Zn(II) have been shown to aggregate a variety of proteins and peptides, including a-synuclein [47,48], prolactin [49], creatine kinase [50], a-lactalbumin [51], hemoglobin [52,53], chymotrypsin (T.P. Silverstein, unpublished results) and the b-amyloid [54][55][56][57][58][59][60] and prion peptides [61,62].…”

Bioavailability of silver nanoparticles and ions: from a chemical and biochemical perspective

“…The presence of cysteine and other amino acids in the fish cell medium (Leibovitz's L-15) is likely to influence the toxic effects of Ag NPs, if experiments are carried out with the full medium including serum. Also proteins typically contain thiol groups, to which Ag þ may strongly bind and possibly replace essential metal ions [74,75]. Binding of Ag(I) to natural organic ligands was shown to be very strong at low Ag concentrations and was assumed to be due to the presence of thiol ligands [66].…”

“…Interactions of dissolved Ag þ with ions present in experimental media are expected to influence also Ag bioavailability to exposed organisms. Despite the absence of systematic studies, several observations on ameliorating effects of Cl 2 on Ag toxicity to fish [78][79][80], of cysteine to algae [45] and N-acetylcysteine to nematodes [74] suggest that Ag-chloro complexes and Ag-cysteine (or Ag-Nacetylcysteine) complexes are not internalized in cells. Moreover, uptake experiments with algae that make use of cysteine to remove Ag adsorbed to cell surfaces indicate that Agcysteine complexes are not taken up by algae [46].…”