Role of amino acids at positions 34, 296, and 486 of cytochrome P450 2D6 in the stimulatory and inhibitory effects of psychotropic agents on dopamine formation from p-tyramine

The effects of psychotropic agents such as fluvoxamine, fluoxetine, paroxetine, milnacipran, and fluphenazine on dopamine formation from p-tyramine catalysed by cytochrome P450 (CYP) 2D6.2 (Arg296Cys;Ser486Thr), CYP2D6.10 (Pro34Ser;Ser486Thr), and CYP2D6.39 (Ser486Thr) were compared with the effects on dopamine formation from p-tyramine by CYP2D6.1. Michaelis constants (Km) and maximal velocity (kcat) values for dopamine formation and inhibition constants (Ki) of the psychotropic agents were determined.For CYP2D6.39, the kcat values for fluvoxamine, fluoxetine, and milnacipran, but not for paroxetine and fluphenazine, gradually increased with increasing concentrations, indicating activation of the catalysed reaction.Fluphenazine competitively inhibited dopamine formation catalysed by all variants, with a higher Ki value for CYP2D6.10. Among the three compounds that have a trifluoromethyl group in their chemical structure, only fluvoxamine and fluoxetine, as well as milnacipran that does not have this group, decreased Km values and/or increased kcat values for dopamine formation, suggesting that the group may not be essential for the activation.These findings indicate that substitution of amino acids at positions 34 and 486 can affect the affinity (Km) and enzymatic activity (kcat), respectively, for milnacipran and that the effect of substitution of arginine to cysteine at the 296th position on the activation would be effector dependent.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:51

Enthalten in:

Xenobiotica; the fate of foreign compounds in biological systems - 51(2021), 11 vom: 04. Nov., Seite 1229-1235

Sprache:

Englisch

Beteiligte Personen:

Niwa, Toshiro [VerfasserIn]
Arima, Juri [VerfasserIn]
Michihiro, Yurina [VerfasserIn]

Links:

Volltext

Themen:

41VRH5220H
Amino Acids
CYP2D6
Cytochrome P-450 CYP2D6
Dopamine
Dopamine formation
EC 1.14.14.1
Fluphenazine
Genetic polymorphism
Journal Article
Milnacipran
Paroxetine
Selective serotonin reuptake inhibitor (SSRI)
Serotonin Uptake Inhibitors
Tyramine
VTD58H1Z2X
X8ZC7V0OX3

Anmerkungen:

Date Completed 03.12.2021

Date Revised 07.12.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1080/00498254.2021.1989520

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM331470233