Small copper carrier explained

Small copper carrier or SCC is a small molecule that transports copper in urine. It is excreted in the kidneys in humans or mice where the liver is unable to excrete excess copper in bile. This happens in Wilson’s disease where the presence of copper in urine is a diagnostic.^[1] It was discovered by Lawrence Wilson Gray and Svetlana Lutsenko.^[2] The molecule is 2 kDa. Its exact nature is not yet known but is presumed to be a peptide.^[3]

The same peptide also appears in blood and urine of many different mammals. Its copper free molecular weight is 1329.5.^[4] In neutral conditions the small copper carrier molecule has a negative charge. Copper is bound to the carrier via oxygen and nitrogen (O or N).^[5]

References

1. Web site: Copper's previously unknown exit strategy. 13 July 2012. 14 July 2012.
2. Web site: Mechanisms of Homeostatic Control of Copper in Tissues . Database for Research Grants. Gray. Wilson Lawrence. 14 July 2012.
3. Gray. Lawrence. Fangyu Peng . Shannon A. Molloy . Venkata S. Pendyala . Abigael Muchenditsi . Otto Muzik . Jaekwon Lee . Jack H. Kaplan . Svetlana Lutsenko . 2012. Urinary Copper Elevation in a Mouse Model of Wilson's Disease Is a Regulated Process to Specifically Decrease the Hepatic Copper Load. PLOS ONE. 7. 6. e38327. 1932-6203. 10.1371/journal.pone.0038327. 2012PLoSO...738327G . 22802922 . 3390108. free.
4. Miguel Tellez . Travis Alsky . Matthew Dalphin . Stephen Flynn. Arturo Munoz . Denise Ibarra. Helen Truong . Maria C Linder. Svetlana Lutsenko . Scott Weldy. Purification and characterization of a small copper carrier found in mammalian blood plasma and in the urine of mice and dogs with copper overload. FASEB Journal. April 2016. 30. 1. 10.1096/fasebj.30.1_supplement.1026.2. 88742702 . free.
5. Linder . Maria C. . Copper Homeostasis in Mammals, with Emphasis on Secretion and Excretion. A Review . International Journal of Molecular Sciences . 13 July 2020 . 21 . 14 . 4932 . 10.3390/ijms21144932. 32668621 . 7403968 . free .