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Research Article Free access | 10.1172/JCI105566
Department of Paediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
†Senior Research Fellow, The Research Institute, The Hospital for Sick Children, Toronto.
‡Address requests for reprints to Dr. Andrew Sass-Kortsak, 555 University Avenue, Toronto, Ontario, Canada.
*Submitted for publication May 31, 1966; accepted December 30, 1966.
Supported by funds from The Medical Research Council of Canada.
A preliminary report of this investigation was presented at the Seventeenth Scientific Meeting of the Protein Foundation, Cambridge, Mass., and published in Vox Sang. (Basel), 1963, 8, 111.
Find articles by Neumann, P. in: JCI | PubMed | Google Scholar
Department of Paediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
†Senior Research Fellow, The Research Institute, The Hospital for Sick Children, Toronto.
‡Address requests for reprints to Dr. Andrew Sass-Kortsak, 555 University Avenue, Toronto, Ontario, Canada.
*Submitted for publication May 31, 1966; accepted December 30, 1966.
Supported by funds from The Medical Research Council of Canada.
A preliminary report of this investigation was presented at the Seventeenth Scientific Meeting of the Protein Foundation, Cambridge, Mass., and published in Vox Sang. (Basel), 1963, 8, 111.
Find articles by Sass-Kortsak, A. in: JCI | PubMed | Google Scholar
Published April 1, 1967 - More info
In addition to copper bound to ceruloplasmin and to albumin, there is a third small fraction of copper in human serum that is bound to amino acids. The amino acid-bound fraction of copper is in equilibrium with albumin-bound copper, and both fractions are probably in equilibrium with ionic copper.
Of the 23 amino acids that are known to be in human serum, a substantial number were shown (in physiological concentrations) to compete effectively with albumin for the binding of copper. In this respect, histidine had the most marked effect followed by glutamine, threonine, cystine, and others. The effect of the combined presence of 23 amino acids on the state of copper in human serum could not be explained on the basis of their individual abilities to compete with albumin for the binding of copper. It is suggested that copper may also be present in serum in the form of mixed amino acid-copper complexes consisting of one atom of copper and two different amino acids. Under normal conditions, histidine is the amino acid primarily involved in the formation of mixed amino acid-copper complexes in serum. In combination with histidine and copper, threonine, glutamine, and asparagine are the other amino acids that are most likely to be the third members of these mixed complexes.
The first binding site for copper on human albumin is different from subsequent ones in that its binding affinity to copper is much higher. We propose that the amino acid-bound fraction of copper in serum may have a physiological role in the biological transport of copper.