Abstract
Oxidative biocatalytic reactions performed by cytochrome P450 enzymes (P450s) are of high interest for the chemical and pharmaceutical industries. CYP267B1 is a P450 enzyme from myxobacterium Sorangium cellulosum So ce56 displaying a broad substrate scope. In this work, a search for new substrates was performed, combined with product characterization and a structural analysis of substrate-bound complexes using X-ray crystallography and computational docking. The results demonstrate the ability of CYP267B1 to perform in-chain hydroxylations of medium-chain saturated fatty acids (decanoic acid, dodecanoic acid and tetradecanoic acid) and a regioselective hydroxylation of flavanone. The fatty acids are mono-hydroxylated at different in-chain positions, with decanoic acid displaying the highest regioselectivity towards ω-3 hydroxylation. Flavanone is preferably oxidized to 3-hydroxyflavanone. High-resolution crystal structures of CYP267B1 revealed a very spacious active site pocket, similarly to other P450s capable of converting macrocyclic compounds. The pocket becomes more constricted near to the heme and is closed off from solvent by residues of the F and G helices and the B-C loop. The crystal structure of the tetradecanoic acid-bound complex displays the fatty acid bound near to the heme, but in a nonproductive conformation. Molecular docking allowed modeling of the productive binding modes for the four investigated fatty acids and flavanone, as well as of two substrates identified in a previous study (diclofenac and ibuprofen), explaining the observed product profiles. The obtained structures of CYP267B1 thus serve as a valuable prediction tool for substrate hydroxylations by this highly versatile enzyme and will encourage future selectivity changes by rational protein engineering.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.