Chimeric cytochromes P450 engineered by domain swapping and random mutagenesis for producing human metabolites of drugs

• Published in: Biotechnology and bioengineering 2014-07, Vol.111 (7), p.1313-1322
• Main Authors: Kang, Ji-Yeon, Ryu, Sang Hoon, Park, Sun-Ha, Cha, Gun Su, Kim, Dong-Hyun, Kim, Keon-Hee, Hong, Austin W., Ahn, Taeho, Pan, Jae-Gu, Joung, Young Hee, Kang, Hyung-Sik, Yun, Chul-Ho
• Format: Article
• Language: English
• Subjects: Bacillus megaterium; Bacillus megaterium - enzymology; bacterial CYP102A1; biocatalyst; Biocatalysts; Biotechnology; Biotransformation; chimeric enzyme; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Cytochromes P450; domain swapping; Drugs; Enzymes; human drug metabolite; Kinetics; Metabolites; Mutagenesis; Mutant Proteins - genetics; Mutant Proteins - metabolism; Oxidation; Oxidation-Reduction; Pharmaceutical Preparations - metabolism; Protein Engineering; Protein Structure, Tertiary; Proteins; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Reductases; Residues; statin drug; Substrates
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.25202

ABSTRACT Human drug metabolites produced by cytochrome P450 enzymes are critical for safety testing and may themselves act as drugs or leads in the drug discovery and development process. Here, highly active chimeric fusion proteins (chimeras) were obtained by reductase domain swapping of mutants at key catalytic residues of the heme domain with that of a natural variant (CYP102A1.2) of P450 BM3 (CYP102A1.1) from Bacillus megaterium. Random mutagenesis at the heme domain of the chimera was also used to generate chimeric mutants that were more active and diverse than the chimeras themselves. To determine whether the chimeras and several mutants of the highly active chimera displayed enhanced catalytic activity and, more importantly, whether they acquired activities of biotechnological importance, we measured the oxidation activities of the chimeras and chimeric mutants toward human P450 substrates, mainly drugs. Some of the chimeric mutants showed high activity toward typical human P450 substrates including drugs. Statin leads, especially chiral products, with inhibitory effects toward HMG‐CoA reductase could be obtained from metabolites of statin drugs generated using these chimeric mutants. This study reveals the critical role of the reductase domain for the activity of P450 BM3 and shows that chimeras generated by domain swapping can be used to develop industrial enzymes for the synthesis of human metabolites from drugs and drug leads. Biotechnol. Bioeng. 2014;111: 1313–1322. © 2014 Wiley Periodicals, Inc. Highly active chimeric fusion proteins (chimeras) were obtained by reductase domain swapping of mutants at key catalytic residues of the heme domain with that of a natural variant of CYP102A1 from Bacillus megaterium. Random mutagenesis at the heme domain of the chimera was also used to generate chimeric mutants that were more active and diverse than the chimeras themselves. Some of the chimeric mutants showed high activity toward typical human P450 substrates and clinical drugs.