The functional coupling of 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase was investigated in rat liver microsomal vesicles. The activity of both enzymes was latent in intact vesicles, indicating the intraluminal localization of their active sites. Glucose-6-phosphate, a substrate for hexose-6-phosphate dehydrogenase, stimulated the cortisone reductase activity of 11B-hydroxysteroid dehydrogenase type 1. Inhibition of glucose-6-phosphate uptake by S3483, a specific inhibitor of the microsomal glucose-6-phosphate transporter, decreased this effect. Similarly, cortisone increased the intravesicular accumulation of radioactivity upon the addition of radiolabeled glucose-6-phosphate, indicating the stimulation of hexose-6-phosphate dehydrogenase activity. A correlation was shown between glucose-6-phosphate-dependent cortisone reduction and cortisone-dependent glucose-6-phosphate oxidation. The results demonstrate a close cooperation of the enzymes based on co-localization and the mutual generation of cofactors for each other.

Banhegyi, G., Benedetti, A., Fulceri, R., Senesi, S. (2004). Cooperativity between 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase in the lumen of the endoplasmic reticulum. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 279(26), 27017-27021 [10.1074/jbc.M404159200].

Cooperativity between 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase in the lumen of the endoplasmic reticulum

BENEDETTI, A.;FULCERI, R.;SENESI, S.
2004-01-01

Abstract

The functional coupling of 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase was investigated in rat liver microsomal vesicles. The activity of both enzymes was latent in intact vesicles, indicating the intraluminal localization of their active sites. Glucose-6-phosphate, a substrate for hexose-6-phosphate dehydrogenase, stimulated the cortisone reductase activity of 11B-hydroxysteroid dehydrogenase type 1. Inhibition of glucose-6-phosphate uptake by S3483, a specific inhibitor of the microsomal glucose-6-phosphate transporter, decreased this effect. Similarly, cortisone increased the intravesicular accumulation of radioactivity upon the addition of radiolabeled glucose-6-phosphate, indicating the stimulation of hexose-6-phosphate dehydrogenase activity. A correlation was shown between glucose-6-phosphate-dependent cortisone reduction and cortisone-dependent glucose-6-phosphate oxidation. The results demonstrate a close cooperation of the enzymes based on co-localization and the mutual generation of cofactors for each other.
Banhegyi, G., Benedetti, A., Fulceri, R., Senesi, S. (2004). Cooperativity between 11beta-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase in the lumen of the endoplasmic reticulum. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 279(26), 27017-27021 [10.1074/jbc.M404159200].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/21758
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