title: Histochemical quantification of dopa-oxidase (tyrosinase) activity in epidermal melanocytes.
abstract: The graphical method of Lineweaver-Burk was applied to the histochemical system to obtain quantitative information on the dopa-oxidase activity in human epidermal melanocytes. In vitro experiment showed that the incubation time necessary for yielding a certain amount of dopa-melanin is related to the amount of enzyme present. In the case of histochemical experiment, the time required for the first appearance of dopa-melanin deposition in melanocytes at various substrate concentrations was plotted against the reciprocal of the substrate concentration. This technique made it possible to compare the dopa-oxidase activity at various sites of the tissue.
mesh_terms: D000328:Adult; D000818:Animals; D004156:Catechol Oxidase / Q000032:analysis*; D006651:Histocytochemistry; D006801:Humans; D007700:Kinetics; D008297:Male; D008544:Melanocytes / Q000201:enzymology* / Q000528:radiation effects; D051379:Mice; D014442:Monophenol Monooxygenase / Q000032:analysis* / Q000378:metabolism / Q000528:radiation effects; D012867:Skin / Q000201:enzymology* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase