Regio- and Stereoselective Steroid Hydroxylation at C7 by Cytochrome P450 Monooxygenase Mutants.
Li, A., Acevedo-Rocha, C.G., D'Amore, L., Chen, J., Peng, Y., Garcia-Borras, M., Gao, C., Zhu, J., Rickerby, H., Osuna, S., Zhou, J., Reetz, M.T.(2020) Angew Chem Int Ed Engl 59: 12499-12505
- PubMed: 32243054 
- DOI: https://doi.org/10.1002/anie.202003139
- Primary Citation of Related Structures:  
6LY4 - PubMed Abstract: 
Steroidal C7β alcohols and their respective esters have shown significant promise as neuroprotective and anti-inflammatory agents to treat chronic neuronal damage like stroke, brain trauma, and cerebral ischemia. Since C7 is spatially far away from any functional groups that could direct C-H activation, these transformations are not readily accessible using modern synthetic organic techniques. Reported here are P450-BM3 mutants that catalyze the oxidative hydroxylation of six different steroids with pronounced C7 regioselectivities and β stereoselectivities, as well as high activities. These challenging transformations were achieved by a focused mutagenesis strategy and application of a novel technology for protein library construction based on DNA assembly and USER (Uracil-Specific Excision Reagent) cloning. Upscaling reactions enabled the purification of the respective steroidal alcohols in moderate to excellent yields. The high-resolution X-ray structure and molecular dynamics simulations of the best mutant unveil the origin of regio- and stereoselectivity.
Organizational Affiliation: 
School of life science, Hubei University, State Key Laboratory of Biocatalysis and Enzyme Engineering, #368 Youyi Road, Wuhan, 430062, P.R. China.