Human manganese superoxide dismutase is readily detectable by a copper blotting technique

Manganese-superoxide dismutase (MnSOD) in human fibroblast and liver lysates was found to bind copper avidly under the conditions of a copper blotting technique which also detects known copper-binding proteins. Competition studies suggest that the copper-binding site of the molecule under these conditions is distinct from its manganese-binding site. Copper blotting provides a sensitive way to detect MnSOD in human tissues, and may be generally applicable to studies of copper-binding by biological molecules.