Investigation by site-directed mutagenesis of the role of cytochrome P450 2B4 non-active-site residues in protein-ligand interactions based on crystal structures of the ligand-bound enzyme.

ABSTRACT: Residues located outside the active site of cytochromes P450 2B have exhibited importance in ligand binding, structural stability and drug metabolism. However, contributions of non-active-site residues to the plasticity of these enzymes are not known. Thus, a systematic investigation was undertaken of unique residue-residue interactions found in crystal structures of P450 2B4 in complex with 4-(4-chlorophenyl)imidazole (4-CPI), a closed conformation, or in complex with bifonazole, an expanded conformation. Nineteen mutants distributed over 11 sites were constructed, expressed in Escherichia coli and purified. Most mutants showed significantly decreased expression, especially in the case of interactions found in the 4-CPI structure. Six mutants (H172A, H172F, H172Q, L437A, E474D and E474Q)

SUBMITTER: Wilderman PR 

PROVIDER: S-EPMC3911823 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature