L-DOPA BIOSYNTHESIS WITH Agaricus bisporus TYROSINASES ASSISTANCE

L-DOPA (3,4-dihydroxyphenyl-L-alanine) is a drug of choice in Parkinson's disease treatment. However the chemical method of its synthesis has a number of drawbacks, so biotechnological approaches are being explored as an alternative. Aim. The goal is to develop a new affordable and effective method of biosynthesis of L-DOPA using mushroom tyrosinase, immobilized using an economical carrier, which ensures stability and enzyme multiple uses. Methods. Agaricus bisporus isolated tyrosinase was used in the work. L-DOPA biosynthesis was carried out in aqueous and organic medium. The obtained product was analyzed using mass spectrometry, specific rotation and melting point. The enzyme immobilization was carried out in poly-N-vinylpyrrolidone (PVP), the interaction with the carrier, pH-optimum and the application frequency were determined. Results. A partially purified preparation of tyrosinase was isolated from Agaricus bisporus. In aqueous solution in enzyme presence, only 5.1% of L-DOPA was obtained due to the subsequent formation of complex polycyclic compounds. The biosynthesis of L-DOPA derivative in methylene chloride with the addition of a buffer solution made it possible to obtain a product with a yield of 55%. Tyrosinase immobilized in PVP showed activity 30% higher than free in CH2Cl2 medium and carried out biocatalysis for 7 cycles. Conclusions. A method of L-DOPA synthesizing using an available biocatalyst based on immobilized tyrosinase was developed, which enabled to obtain L-DOPA during 7 cycles of use in a methylene chloride medium.