Heterologous expression of human microsomal epoxide hydrolase in saccharomyces cerevisiae: Study of the valpromide-carbamazepine epoxide interaction

A cDNA of human microsomal epoxide hydrolase (hmEH) was constitutively and inducibly expressed in Saccharomyces cerevisiae.The heterologous enzyme was located mainly in the microsomal fraction of yeast cells. Yeast microsomes containing hmEH exerted styrene oxide hydrolase activity ( K m = 300 μM; V...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Biochemical pharmacology 1991-09, Vol.42 (7), p.1367-1372
Hauptverfasser: Eugster, Hans-Pietro, Sengstag, Christian, Hinnen, Albert, Meyer, Urs A., Wügler, Friedrich E.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:A cDNA of human microsomal epoxide hydrolase (hmEH) was constitutively and inducibly expressed in Saccharomyces cerevisiae.The heterologous enzyme was located mainly in the microsomal fraction of yeast cells. Yeast microsomes containing hmEH exerted styrene oxide hydrolase activity ( K m = 300 μM; V max = 22 nmol/mg min) as well as carbamazepine epoxide hydrolase activity. The hmEH catalysed exclusively the formation of carbamazepine-10,11-transdihydrodiol, since no carbamazepine-10, 11-cisdihydrodiol was detected. Inhibition studies using these microsomes revealed unequivocally hmEH as the target for inhibition by the antiepileptic drug valproroide. A K i value of 27 μM was determined for the inhibitor valpromide with styrene oxide as substrate. For carbamazepine epoxide, a K i value of 8.6 μM was obtained, which is well in line with data published for hmEH determined with human liver microsomes. Our results demonstrate the potential of heterologous gene expression in S.cerevisiae and its application to the in vitro study of pharmacological and toxicological problems.
ISSN:0006-2952
1873-2968
DOI:10.1016/0006-2952(91)90447-D