Enzyme-catalyzed regio-selective demethylation of papaverine by CYP105D1.

OBJECTIVES: To investigate the regio-selective demethylation of papaverine by CYP105D1 and develop a whole-cell biocatalytic system for the preparative synthesis of 6-O-demethyl-papaverine.

RESULTS: CYP105D1 from Streptomyces griseus ATCC 13273 was used for the regioselective demethylation of papaverine at C-6 using putidaredoxin reductase (PDR) and putidaredoxin (Pdx) as the electron transport system. The Km value of CYP105D1 towards papaverine was estimated to be 92.24 μM. Furthermore, a CYP105D1-based whole-cell system was established in E. coli BL21(DE3). The whole cell biotransformation condition was optimized as 25 °C, pH 7.5, 8 g (cell dry weight) L-1 whole cell biomass and 3% (v/v) PEG-200 as cosolvent. Under the optimal condition, the conversion yield of papaverine reached to 61.15% within 24 h.

CONCLUSIONS: The selective demethylation of papaverine by CYP105D1 was accomplished. The CYP105D1-based whole-cell biocatalyst has a potential used for the efficient synthesis of 6-O-demethyl-papaverine.