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Publication Abstract from PubMed

Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable with T50 values ~30-40 degrees C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared to related extant forms, but also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. While extant human CYP1B1 has one molecule of alpha-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17beta-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to their thermostability.

Structure of an ancestral mammalian family 1B1 cytochrome P450 with increased thermostability.,Bart AG, Harris KL, Gillam EMJ, Scott EE J Biol Chem. 2020 Mar 10. pii: RA119.010727. doi: 10.1074/jbc.RA119.010727. PMID:32156703^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.