title: Structural and computational insights into the versatility of cadmium binding to proteins.
abstract: Cadmium is a highly toxic group XII metal, similar to zinc and mercury. Unlike zinc, which is one of the most common metal cofactors in biology, cadmium is highly toxic. Many Zn(2+)-binding proteins can bind Cd(2+)-ions without significantly affecting their structures. Here, the protein data bank is analysed with regard to protein-cadmium interactions, which shows that cadmium can bind to a variety of ion binding sites in proteins. Statistical analysis of Cd(2+)-side chain interactions is compared with a similar analysis of other ions. This analysis reveals that with regard to amino acid side-chain preference, Cd(2+) is more similar to Mn(2+) than to Zn(2+) or Hg(2+). Finally, the interaction energies of three native metal binding proteins are calculated where Cd(2+) binds instead of Zn(2+), Ca(2+) or Cu(2+). The interaction energies are decomposed into individual components whose contributions are discussed.
authors.affiliation: Computational Chemistry and Biochemistry Research Group, Department of Chemistry and Biomedical Sciences, Linnæus University, 391 82 Kalmar, Sweden.
authors.forename: Ran
authors.initials: R
authors.lastname: Friedman
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry* / Q000378:metabolism*; D001400:Azurin / Q000737:chemistry* / Q000378:metabolism*; D002104:Cadmium / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008958:Models, Molecular; D010320:Parvalbumins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013816:Thermodynamics
chemical_list: D010320:Parvalbumins; D002104:Cadmium; D001400:Azurin; D000426:Alcohol Dehydrogenase