Role of P34S, G169R, R296C, and S486T Substitutions in Ligand Access and Catalysis for Cytochrome P450 2D6 Allelic Variants CYP2D6*14A and CYP2D6*14B

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BACKGROUND: Genetic polymorphism of cytochrome P450 (CYP) contributes to variability in drug metabolism, clearance, and response. This study aimed to investigate the functional and molecular basis for altered ligand binding and catalysis in CYP2D6*14A and CYP2D6*14B, two unique alleles common in the Asian population.

METHODS: CYP proteins expressed in Escherichia coli were studied using the substrate 3-cyano-7- ethoxycoumarin (CEC) and inhibitor probes (quinidine, fluoxetine, paroxetine, terbinafine) in the enzyme assay. Computer modelling was additionally used to create three-dimensional structures of the CYP2D6*14 variants.

RESULTS: Kinetics data indicated significantly reduced intrinsic clearance in CYP2D6*14 variants, suggesting that P34S, G169R, R296C, and S486T substitutions worked cooperatively to alter the conformation of the active site that negatively impacted the deethylase activity of CYP2D6. For the inhibition studies, IC50 values decreased in quinidine, paroxetine, and terbinafine but increased in fluoxetine, suggesting a varied ligand-specific susceptibility to inhibition. Molecular docking further demonstrated the role of P34S and R296C in altering access channel dimensions, thereby affecting ligand access and binding and subsequently resulting in varied inhibition potencies.

CONCLUSION: In summary, the differential selectivity of CYP2D6*14 variants for the ligands (substrate and inhibitor) was governed by the alteration of the active site and access channel architecture induced by the natural mutations found in the alleles.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:15

Enthalten in:

Drug metabolism and bioanalysis letters - 15(2022), 1 vom: 31., Seite 51-63

Sprache:

Englisch

Beteiligte Personen:

Dong, Amelia Nathania [VerfasserIn]
Ahemad, Nafees [VerfasserIn]
Pan, Yan [VerfasserIn]
Palanisamy, Uma Devi [VerfasserIn]
Yiap, Beow Chin [VerfasserIn]
Ong, Chin Eng [VerfasserIn]

Links:

Volltext

Themen:

01K63SUP8D
41VRH5220H
9035-51-2
CYP2D6*14
Cytochrome P-450 CYP2D6
Cytochrome P-450 Enzyme System
Cytochrome P450
EC 1.14.14.1
Enzyme assay
Fluoxetine
G7RIW8S0XP
ITX08688JL
Journal Article
Ligands
Molecular docking
Paroxetine
Polymorphism
Quinidine
Research Support, Non-U.S. Gov't
Site-directed mutagenesis
Terbinafine

Anmerkungen:

Date Completed 18.08.2022

Date Revised 21.12.2022

published: Print

Citation Status MEDLINE

doi:

10.2174/1872312815666220113125232

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM335840981