Cu-Zn superoxide dismutase-1 (SOD-1) is a well characterized cytosolic scavenger
of oxygen free radicals that requires copper and zinc binding to potentiate
its enzymatic activity. Copper chaperone for SOD-1 (CCS) is essential for the
incorporation of copper into SOD-1, and therefore is necessary for its enzymatic
activity. CCS prevents copper ions from binding to intracellular copper
scavengers and provides the SOD-1 enzyme with the necessary copper cofactor.
CCS escorts copper only to SOD-1 and fails to deliver copper to proteins
in the mitochondria, nucleus or secretory pathway. CCS interacts with both
wildtype and mutated forms of SOD-1 through CCS domains that are homologous
in SOD-1. CCS exists as a homodimer that may form a heterodimer with
SOD-1 during copper loading. While many tissues express CCS, the chaperone
is most abundant in the kidney, liver and Purkinje cells in the neuropil of the
central nervous system. The gene for CCS maps to human chromosome 11q13.