[Tyrosinases of the pigmented portions of the eye in 4 species of rodent].

Ocular tyrosinases of choroid from adult Rabbit, Rat, Hamster and Guinea pig are separated by gel electrophoresis. A single tyrosinase is found in all mammalian species investigated, it is present in pigmented strains and lacking in albino ones. Molecular weights of those enzymes, as determined by polyacrilamide gradient gel electrophoresis, are about 67,000. Involvement of ocular mammalian tyrosinases in in vitro L tyrosine oxidation has been demonstrated.