Identifying cytochrome p450 functional networks and their allosteric regulatory elements.
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2013-12-06
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Abstract
Cytochrome P450 CYP enzymes play key roles in drug metabolism and adverse drug drug interactions Despite tremendous efforts in the past decades essential questions regarding the function and activity of CYPs remain unanswered Here we used a combination of sequence based co evolutionary analysis and structure based anisotropic thermal diffusion ATD molecular dynamics simulations to detect allosteric networks of amino acid residues and characterize their biological and molecular functions We investigated four CYP subfamilies CYP1A CYP2D CYP2C and CYP3A that are involved in 90 of all metabolic drug transformations and identified four amino acid interaction networks associated with specific CYP functionalities i e membrane binding heme binding catalytic activity and dimerization Interestingly we did not detect any co evolved substrate binding network suggesting that substrate recognition is specific for each subfamily Analysis of the membrane binding networks revealed that different CYP proteins adopt different membrane bound orientations consistent with the differing substrate preference for each isoform The catalytic networks were associated with conservation of catalytic function among CYP isoforms whereas the dimerization network was specific to different CYP isoforms We further applied low temperature ATD simulations to verify proposed allosteric sites associated with the heme binding network and their role in regulating metabolic fate Our approach allowed for a broad characterization of CYP properties such as membrane interactions catalytic mechanisms dimerization and linking these to groups of residues that can serve as allosteric regulators The presented combined co evolutionary analysis and ATD simulation approach is also generally applicable to other biological systems where allostery plays a role