New Insights into the Interaction of Class II Dihydroorotate Dehydrogenases with Ubiquinone in Lipid Bilayers as a Function of Lipid Composition.
Int J Mol Sci
; 23(5)2022 Feb 23.
Article
em En
| MEDLINE
| ID: mdl-35269583
ABSTRACT
The fourth enzymatic reaction in the de novo pyrimidine biosynthesis, the oxidation of dihydroorotate to orotate, is catalyzed by dihydroorotate dehydrogenase (DHODH). Enzymes belonging to the DHODH Class II are membrane-bound proteins that use ubiquinones as their electron acceptors. We have designed this study to understand the interaction of an N-terminally truncated human DHODH (HsΔ29DHODH) and the DHODH from Escherichia coli (EcDHODH) with ubiquinone (Q10) in supported lipid membranes using neutron reflectometry (NR). NR has allowed us to determine in situ, under solution conditions, how the enzymes bind to lipid membranes and to unambiguously resolve the location of Q10. Q10 is exclusively located at the center of all of the lipid bilayers investigated, and upon binding, both of the DHODHs penetrate into the hydrophobic region of the outer lipid leaflet towards the Q10. We therefore show that the interaction between the soluble enzymes and the membrane-embedded Q10 is mediated by enzyme penetration. We can also show that EcDHODH binds more efficiently to the surface of simple bilayers consisting of 1-palmitoyl, 2-oleoyl phosphatidylcholine, and tetraoleoyl cardiolipin than HsΔ29DHODH, but does not penetrate into the lipids to the same degree. Our results also highlight the importance of Q10, as well as lipid composition, on enzyme binding.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ubiquinona
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Escherichia coli
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Di-Hidro-Orotato Desidrogenase
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Bicamadas Lipídicas
Limite:
Humans
Idioma:
En
Revista:
Int J Mol Sci
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Suécia