Comparative analysis of metal binding characteristics of copper chaperone proteins, Atx1 and ATOX1.

The metal binding properties of the human copper chaperone ATOXI and its yeast homologue Atxl have been characterized. Complexes of these proteins with Cu(I), Ag (1), Cd(II) and Hg(II) were studied by native gel electrophoresis, chemical cross-linking followed by SDS-PAGE, as well as by size exclusion chromatography, mutagenesis and UV-visible absorption spectroscopy. Results indicate that binding of different metals to either ATOXI or Atxl altered conformation of subunit structure and the oligomerization state of the proteins.

Characterization and copper binding properties of human COMMD1 (MURR1).

COMMD1 (copper metabolism gene MURR1 (mouse U2af1-rs1 region1) domain) belongs to a family of multifunctional proteins that inhibit nuclear factor NF-kappaB. COMMD1 was implicated as a regulator of copper metabolism by the discovery that a deletion of exon 2 of COMMD1 causes copper toxicosis in Bedlington terriers. Here, we report the detailed characterization and specific copper binding properties of purified recombinant human COMMD1 as well as that of the exon 2 product, COMMD(61-154).

Identification of the "missing domain" of the rat copper-transporting ATPase, atp7b: insight into the structural and metal binding characteristics of its N-terminal copper-binding domain.

Wilson disease is an autosomal disorder of copper transport caused by mutations in the ATP7B gene encoding a copper-transporting P-type ATPase. The Long Evans Cinnamon (LEC) rat is an established animal model for Wilson disease. We have used structural homology modelling of the N-terminal copper-binding region of the rat atp7b protein (rCBD) to reveal the presence of a domain, the fourth domain (rD4), which was previously thought to be missing from rCBD.

Protein disulfide isomerase, a multifunctional protein chaperone, shows copper-binding activity.

Protein disulfide isomerase (PDI) is a 55 kDa multifunctional protein of the endoplasmic reticulum (ER) involved in protein folding and isomerization. In addition to the chaperone and catalytic functions, PDI is a major calcium-binding protein of the ER. Although the active site of PDI has a similar motif CXXC to the Cu-binding motif in Wilson and Menkes proteins and in other copper chaperones, there has been no report on any metal-binding capability of PDI other than calcium binding.

Identification of metal-binding proteins in human hepatoma lines by immobilized metal affinity chromatography and mass spectrometry.

The metalloproteome is defined as the set of proteins that have metal-binding capacity by being metalloproteins or having metal-binding sites. A different metalloproteome may exist for each metal. Mass spectrometric characterization of metalloproteomes provides valuable information relating to cellular disposition of metals physiologically and in metal-associated diseases.