Cross-Linked Aggregates of Tyrosinase for the Efficient Synthesis of L-DOPA.

L-3,4-dihydroxyphenylalanine (L-DOPA or Levodopa) is widely used to treat Parkinson's disease, but its large-scale chemical synthesis is costly and environmentally challenging. This study investigates the enzymatic conversion of L-tyrosine to L-Dopa to enhance efficiency and yield without any potential racemization. Tyrosinase, extracted from button mushrooms, was immobilized as cross-linked enzyme aggregates (TY CLEAs), achieving an activity of 31.32 units/g. Commercially available skim milk served as a protein feeder and demonstrated antioxidant properties, helping prevent the formation of L-dopachrome as a byproduct by inhibiting the sequential oxidation of L-dopaquinone, along with ascorbic acid as a reducing agent. We evaluated the stability of TY CLEAs under varying temperatures, pH levels, and organic solvents. High productivity of 1210.95 mgL h was achieved using 10 units of enzyme at a substrate concentration of 15 mM with the use of a surfactant.