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Poison Ivy "Urushiol" 2959 of Via; m.p. 192.5-194°with previous softening. From the mother liquor by concentration and addition of water there was obtained an additional 161 mg., m.p. 189-192°, bubbles in melt, clear at 199°; 91% yield (two fractions).

When exposed to either sodium dodecyl sulfate or guanidinium chloride, ascorbate oxidase (molecular weight 140,000, 8-10 copper atoms) dissociates into two copper-free subunits, each of about half the molecular weight of the native enzyme. Removal of the denaturant results in aggregation of the subunits and it has not been found possible to restore the copper and activity. All evidence indicates that the two subunits of molecular weight 65,000, comprising the native enzyme, are identical. Treatment of the native enzyme with sodium dodecyl sulfate and either 2-mercaptoethanol or 2mercaptoethylamine results in two new bands on sodium dodecyl sulfate electrophoresis. The components corresponding to these bands have molecular weights of 38,000 (A chain) and 28,000 (B chain). The same two components are obtained when disulfides of the native enzyme are cleaved with cyanide.

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