Albumin-bound copper (Cu-HSA)

Albumin-bound copper represents the primary fraction of the exchangeable copper pool in human plasma, serving as a critical transport mechanism for copper ions between the gastrointestinal tract, liver, and peripheral tissues (El Balkhi et al., 2011, Analytical and Bioanalytical Chemistry). Human serum albumin (HSA) binds copper(II) ions with high affinity at its N-terminal Asp-Ala-His-Lys (DAHK) motif, which prevents the formation of reactive oxygen species and ensures safe delivery to cellular transporters (Zunszain et al., 2003, BMC Structural Biology). In pathological states such as Wilson's disease, the regulation of this pool is disrupted, leading to an increase in non-ceruloplasmin-bound copper that can cause oxidative damage to the liver and central nervous system (EASL Clinical Practice Guidelines, 2012, Journal of Hepatology). Therapeutic interventions often target this specific copper fraction using chelating agents like penicillamine or trientine, which facilitate the mobilization and urinary excretion of the metal (Roberts & Schilsky, 2008, Hepatology). Newer agents, such as choline tetrathiomolybdate, form stable complexes with albumin-bound copper to prevent its uptake into tissues, thereby mitigating systemic copper toxicity (Brewer et al., 2006, Archives of Neurology). Monitoring the levels of albumin-bound copper, often measured as part of the exchangeable copper (CuEXC) fraction, is essential for diagnosing copper metabolism disorders and evaluating the efficacy of decoppering therapies.

Other names

Copper-albumin complexExchangeable copperNon-ceruloplasmin copperAlbumin-Cu(II)Labile copper pool

Chelation of the exchangeable copper pool to facilitate urinary excretion or the formation of stable tripartite complexes with albumin to prevent tissue uptake and promote biliary excretion.