Drug metabolite synthesis by immobilized human FMO3 and whole cell catalysts

Tingjie Zheng,Chongliang Gao

doi:10.1186/s12934-019-1189-7

Abstract

BackgroundSufficient reference standards of drug metabolites are required in the drug discovery and development process. However, such drug standards are often expensive or not commercially available. Chemical synthesis of drug metabolite is often difficulty due to the highly regio- and stereo-chemically demanding. The present work aims to construct stable and efficient biocatalysts for the generation of drug metabolites in vitro.ResultIn this work, using benzydamine as a model drug, two easy-to-perform approaches (whole cell catalysis and enzyme immobilization) were investigated for the synthesis of FMO3-generated drug metabolites. The whole cell catalysis was carried out by using cell suspensions of E. coli JM109 harboring FMO3 and E. coli BL21 harboring GDH (glucose dehydrogenase), giving 1.2 g/L benzydamine N-oxide within 9 h under the optimized conditions. While for another approach, two HisTrap HP columns respectively carrying His6-GDH and His6-FMO3 were connected in series used for the biocatalysis. In this case, 0.47 g/L benzydamine N-oxide was generated within 2.5 h under the optimized conditions. In addition, FMO3 immobilization at the C-terminal (membrane anchor region) significantly improved its enzymatic thermostability by more than 10 times. Moreover, the high efficiency of these two biocatalytic approaches was also confirmed by the N-oxidation of tamoxifen.ConclusionsThe results presented in this work provides new possibilities for the drug-metabolizing enzymes-mediated biocatalysis.

Highlights

Sufficient reference standards of drug metabolites are required in the drug discovery and development process
The results presented in this work provides new possibilities for the drug-metabolizing enzymes-mediated biocatalysis
Purification and spectroscopic characterization of flavin-containing monooxygenase isoform 3 (FMO3) and glucose dehydrogenase (GDH) FMO3 and GDH were successfully expressed in E. coli and purified by Ni-affinity chromatography

Summary

Introduction

Sufficient reference standards of drug metabolites are required in the drug discovery and development process. Such drug standards are often expensive or not commercially available. Chemical synthesis of drug metabolite is often difficulty due to the highly regio- and stereo-chemically demanding. In the course of drug discovery and development process, sufficient reference standards of drug metabolites are required for their pharmacologic and toxicologic characterization [2]. Such drug standards are often expensive or not commercially available, in the case of preclinical/clinical or new therapeutic drugs. In this work, using benzydamine as a model drug, two approaches were tested and optimized for the

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Conclusion