Two copper-containing proteins from white and gray matter of brain.

The procedure for the isolation of two water soluble copper-containing proteins from the white and gray matter of bovine brain is described. One of the proteins, cerebrocuprein I, is superoxide dismutase; and three molecular forms of this enzyme are to be found in brain. The other protein present in gray and white matter is devoid of superoxide dismutase and amine oxidase activities. The amino acid composition, molecular weight, isoelectric point and copper content of this protein were determined. The effect of some agents, pH and thermal treatment of the optical and EPR spectra of the protein were also studied. The copper of the protein may be removed and the holoprotein reconstituted again from apoprotein and copper. The results obtained led to the conclusion that in brain a new copper protein is discovered, which is named neurocuprein.