Abstract
Summary Fifty-one compounds were studied for their ability to compete with the sulfhydryl group for cupric ions. The sulfhydryl-disulfide interchange reactions occurring during the reaction between cysteine and bis (p-nitrophenyl) disulfide and during the course of the denaturation of human serum gamma globulin by heat were used as models for this reaction. Hydralazine, a compound which has been reported to induce a disease resembling systemic lupus erythematosus was exceptionally active in reactivating the sulfhydryl-disulfide interchange reaction when this reaction was studied in the presence of cupric ion.