CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA : IV. DEMONSTRATION OF COPPER IN THE PURIFIED VIRUS.

A search by means of spectroscopic and enzymatic techniques has failed to demonstrate either cytochrome or cytochrome oxidase in purified elementary bodies of vaccinia. A constituent of the virus which catalyzes the oxidation of cystein has been found and identified as copper in a concentration amounting to 0.05 per cent of the dry weight of the virus. The copper constituent was not removed by repeated washing, ultrafiltration, dialysis against 0.1 molar potassium cyanide, or by electrodialysis over a pH range which did not inactivate the virus. During the process of purification of the virus a 25-fold increase of the copper constituent was observed. Emission spectra obtained from the dry virus also revealed copper but no significant traces of other metallic substances. No biological rôle can yet be ascribed to the copper component of virus.