Serum tyrosinase in malignant disease, its activity, and the electrophoretic patterns of the enzyme as carried by immunoglobulins'.

Serum tyrosinase activity in many persons with metastatic diseases was found to be significantly higher than activity in normal persons. The highest activity was observed in melanoma and breast carcinoma. The electrophoretic patterns of serum tyrosinase, resolved by electrophoresis of a serum tyrosinase fraction followed by incubation of the gel sample with L-dopa, and represented as sets of RF's of melanin bands, were characteristically different in melanoma, breast carcinoma, and certain other diseases. The RF's of melanin and protein bands in the serum enzyme preparations from melanoma patients were concisely defined. Further, some potent serum fractions inhibiting tyrosinase melanogenic activity have been obtained, and the presence of tyrosinase inhibitors in the serum enzyme preparation has also been demonstrated. More detailed exploration of these serum tyrosinase parameters may provide more specific and sensitive detection for certain malignant diseases.