title: Presence of tyrosinase activity in human ciliary body.
abstract: We examined tyrosinase activity in pigmented tissues from five human eyes. Tissue extract was prepared in cholate-phosphate buffer by homogenization, centrifugation, trypsin digestion and hydroxylapatite column chromatography. Tyrosinase activity was spectrophotometrically assayed as dopa (L-3,4-dihydroxylphenylalanine) oxidase activity. Tyrosinase activity was detected in the extracts of the ciliary body. Enzyme activity was inhibited by phenylthiourea but not by 3-iodo-tyrosine. We believe that our findings confirm the presence of tyrosinase activity in the human ciliary body.
mesh_terms: D000368:Aged; D004156:Catechol Oxidase / Q000378:metabolism*; D002924:Ciliary Body / Q000201:enzymology*; D004295:Dihydroxyphenylalanine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D013053:Spectrophotometry / Q000379:methods
chemical_list: D004295:Dihydroxyphenylalanine; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase