摘要
The cytochrome P450 enzyme CYP-sb21 from the rare actinomycete Sebekia benihana is capable of hydroxylating the immunosuppressive drug molecule cyclosporine A(CsA)primarily at the 4th N-methyl leucine(MeLeu4),giving rise toγ-hydroxy-N-methyl-L-Leu4-CsA(CsA-4-OH).This oxidative modification of CsA leads to dramatically reduced immunosuppressive activity while retaining the hair growth-promoting side-effect,thus demonstrating great application potential in both pharmaceutical and cosmetic industries.However,this P450 enzyme also hydroxylates CsA at the unwanted position of the 9th N-methyl leucine(MeLeu9),indicating that the regioselectivity needs to be improved for the development of CsA-4-OH into a commercial hair growth stimulator.Herein,we report the crystal structure of CYP-sb21 in its substrate-free form at 1.85Å.Together with sequence and 3D structure comparisons,Autodock-based substrate docking,molecular dynamics(MD)simulation,and site-directed mutagenesis,we identified a number of key residues including R294,E264,and M179 that can improve catalytic efficiency or change the regioselectivity of CYP-sb21 towards CsA,setting the stage for better enzymatic preparation of CsA-4-OH.This study also provides new insights into the substrate recognition and binding mechanism of P450 enzymes that accommodate bulky substrates.
基金
This work was supported by the National Key Research and Development Program of China(2019YFA0905100 to S.L.)
the National Natural Science Foundation of China(31800664 to F.L.,31872729 to S.L.and 31600045 to L.M.)
General Support from China Postdoctoral Science Foundation(Grant No.2017M622293 to F.L.)
Shandong Provincial Natural Science Foundation,China(ZR2019ZD22 to S.L.and ZR2016CQ05 to L.M.)
the Applied Basic Research Programs of Science and Technology of Qingdao(17-1-1-60-jch to L.M.)
National Research Foundation of Korea(No.NRF-2017R1A2A2A05069859 to E.-S.K.).
作者简介
Corresponding author:Fengwei Li,E-mail addresses:lifengwei@sdu.edu.cn;Corresponding author:Eung-Soo Kim,E-mail addresses:eungsoo@inha.ac.kr;Corresponding author:Shengying Li,E-mail addresses:lishengying@sdu.edu.cn。
