Isolation of soluble tyrosinase from human melanoma cells.
In the human melanoma cell tyrosinase exists in a membraneous and a soluble form. The membraneous enzyme has an N-terminal amino acid sequence identical to that predicted from a human c-DNA clone by Kwon et al.. The soluble form has now been isolated by a technique mainly based on the trypsin resistence of the enzyme and the use of hydrophobic interaction chromatography. The specific dopa oxidase activity of the soluble enzyme was 300 mumol/min x mg protein. On isoelectric focusing the enzyme was found in at least ten bands, pI between 3.8-4.6. The molecular weight was found to be 53,000 D. The N-terminal amino acid sequence was the same as that found in the membrane bound form of the enzyme, i.e. the protein maps at the c-albino locus.
Wittbjer
A
A
Department of Pharmacology, University of Lund, Sweden.
Odh
G
G
Rosengren
A M
AM
Rosengren
E
E
Rorsman
H
H
D000595:Amino Acid Sequence; D002460:Cell Line; D006801:Humans; D008546:Melanoma, Experimental / Q000473:pathology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000302:isolation & purification*; D014407:Tumor Cells, Cultured / Q000737:chemistry*
D014442:Monophenol Monooxygenase