Glutathionedopa in malignant melanoma.

A human melanoma metastasis was found to contain a substance identical with synthetic glutathionedopa when examined by means of an automatic amino acid analyser, chromatography on a Dowex-50 column, thin-layer electrophoresis, and by fluorimetry. The presence of glutathionedopa in melanoma tissue and of enzymes capable of hydrolysing the glutathione moiety of the molecule, together with the absence of glutathionedopa in the urine, suggest that glutathionedopa is an intermediate substance in the formation of 5-S-cysteinyldopa.