title: Tyrosinase of hamster melanoma: its purification and estimation by radioimmunoassay.
abstract: 1. Tyrosinase was purified from melanosomal fraction of hamster melanoma. 2. A radioimmunoassay was developed to quantitate the tyrosinase protein in hamster serum and hamster melanoma tissue using polyclonal anti-tyrosinase antibodies and 125I-labeled enzyme. 3. The serum tyrosinase levels were found to be about 0.24 micrograms and 1.14-4.48 micrograms/ml in normal hamsters and melanoma-bearing hamsters, respectively. 4. Tyrosinase protein in serum correlated significantly with the enzyme activity in hamsters with melanoma (r = 0.733). 5. In the cytosol fraction of hamster melanoma, a level of 2.2 micrograms of tyrosinase/mg protein was determined. 6. The usefulness and possible applications of the tyrosinase radioimmunoassay are discussed.
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000302:isolation & purification*; D006224:Cricetinae; D007700:Kinetics; D008546:Melanoma, Experimental / Q000201:enzymology*; D008647:Mesocricetus; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008970:Molecular Weight; D014442:Monophenol Monooxygenase / Q000302:isolation & purification* / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase