Allosteric Interactions in Human Cytochrome P450 CYP3A4: The Role of Phenylalanine 213

Biochemistry. 2019 Mar 12;58(10):1411-1422. doi: 10.1021/acs.biochem.8b01268. Epub 2019 Feb 28.

Abstract

The role of Phe213 in the allosteric mechanism of human cytochrome P450 CYP3A4 was studied using a combination of progesterone (PGS) and carbamazepine (CBZ) as probe substrates. We expressed, purified, and incorporated into POPC Nanodiscs three mutants, F213A, F213S, and F213Y, and compared them with wild-type (WT) CYP3A4 by monitoring spectral titration, the rate of NADPH oxidation, and steady-state product turnover rates with pure substrates and substrate mixtures. All mutants demonstrated higher activity with CBZ, lower activity with PGS, and a reduced level of activation of CBZ epoxidation by PGS, which was most pronounced in the F213A mutant. Using all-atom molecular dynamics simulations, we compared the dynamics of WT CYP3A4 and the F213A mutant incorporated into the lipid bilayer and the effect of the presence of the PGS molecule at the allosteric peripheral site and evaluated the critical role of Phe213 in mediating the heterotropic allosteric interactions in CYP3A4.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Allosteric Site
  • Carbamazepine / chemistry
  • Cytochrome P-450 CYP3A / genetics*
  • Cytochrome P-450 CYP3A / metabolism*
  • Cytochrome P-450 CYP3A / physiology
  • Cytochrome P-450 Enzyme System / metabolism
  • Cytochrome P-450 Enzyme System / physiology
  • Humans
  • Hydroxylation
  • Kinetics
  • Molecular Dynamics Simulation
  • Oxidation-Reduction
  • Phenylalanine / metabolism*
  • Phenylalanine / physiology
  • Progesterone / chemistry

Substances

  • Carbamazepine
  • Phenylalanine
  • Progesterone
  • Cytochrome P-450 Enzyme System
  • Cytochrome P-450 CYP3A