A kinetic study of the melanization pathway between L-tyrosine and dopachrome.
In the pathway of melanin biosynthesis originating from L-tyrosine, the dopachrome accumulation at physiological pH is produced with a pronounced lag period, during which the level of L-dopa increases, following a sigmoidal kinetics to reach a steady-state. A kinetic model has been proposed for the overall pathway of melanization from L-tyrosine to dopachrome; it explains the lag period present during the dopachrome accumulation as well as the influence of L-tyrosine and tyrosinase over this lag period. Use of this model is also valid to explain the kinetics of L-dopa accumulation in the reaction medium, as has been tested by simulation.
D000818:Animals; D004817:Epidermis / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D045563:Indolequinones; D007211:Indoles / Q000378:metabolism*; D007700:Kinetics; D007980:Levodopa / Q000378:metabolism; D008543:Melanins / Q000096:biosynthesis*; D008954:Models, Biological; D014442:Monophenol Monooxygenase / Q000378:metabolism; D011809:Quinones / Q000378:metabolism*; D011893:Rana esculenta; D014443:Tyrosine / Q000378:metabolism*
D045563:Indolequinones; D007211:Indoles; D008543:Melanins; D011809:Quinones; C001123:dopachrome; D014443:Tyrosine; D007980:Levodopa; D014442:Monophenol Monooxygenase