Highly efficient biocatalytic synthesis of l-DOPA using in situ immobilized Verrucomicrobium spinosum tyrosinase on polyhydroxyalkanoate nano-granules

摘要: l-DOPA (3,4-dihydroxyphenyl-l-alanine) is a preferred drug for Parkinson’s disease, and currently in great demand every year worldwide. Biocatalytic conversion of l-tyrosine by tyrosinases the most promising method low-cost production both research industry. Yet, it has been hampered low productivity, rate, stability biocatalyst, tyrosinase. An alternative tyrosinase TyrVs from Verrucomicrobium spinosum with more efficient expression heterologous host better than commercially available Agaricus bisporus was identified this study. Additionally, prepared as novel nano-biocatalyst based on distinct one-step situ immobilization surface polyhydroxyalkanoate (PHA) nano-granules. The resulting PHA-TyrVs nano-granules demonstrated improved l-DOPA-forming monophenolase activity 9155.88 U/g (Tyr protein), which 3.19-fold higher that free TyrVs. also exhibited remarkable thermo-stability, an optimal temperature 50 °C, maintained 70% initial after incubation at 55 °C 24 h. And enhanced affinity copper ion observed nano-granules, making them even biocatalysts production. Therefore, considerable productivity l-DOPA, amounting to 148.70 mg/L h, rate 90.62% can be achieved 3 h biocatalysis under optimized conditions, without significant loss enzyme or yield 8 cycles repeated use. Our study provides excellent robust cost-effective l-DOPA.