Characterization of high-H2O2-tolerant bacterial cytochrome P450 CYP105D18: insights into papaverine N-oxidation

Abstract

The bacterial CYP105 family is involved in secondary metabolite biosynthetic pathways and plays essential roles in the biotransformation of xenobiotics. This study was conducted to investigate the newly identified H2O2-mediated CYP105D18 from Streptomyces laurentii as the first bacterial CYP for N-oxidation. The catalytic efficiency of CYP105D18 for papaverine N-oxidation was 1.43 sec-1 μM-1. The heme oxidation rate (k) was low (<0.3 min-1) in the presence of 200 mM H2O2. This high H2O2 tolerance capacity of CYP105D18 led to higher turnover prior to heme oxidation. Additionally, the high-resolution papaverine complexed structure and substrate-free structure of CYP105D18 were determined. Structural analysis and activity assay results revealed that CYP105D18 had a strong substrate preference for papaverine because of its bendable structure. These findings establish a basis for biotechnological applications of CYP105D18 in the pharmaceutical and medicinal industries.