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Concise Publication Free access | 10.1172/JCI107660
Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
Department of Physiology, Harvard Medical School, Boston, Massachusetts 02115
Find articles by Beckman, B. in: JCI | PubMed | Google Scholar
Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
Department of Physiology, Harvard Medical School, Boston, Massachusetts 02115
Find articles by Flores, J. in: JCI | PubMed | Google Scholar
Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
Department of Physiology, Harvard Medical School, Boston, Massachusetts 02115
Find articles by Witkum, P. in: JCI | PubMed | Google Scholar
Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
Department of Physiology, Harvard Medical School, Boston, Massachusetts 02115
Find articles by Sharp, G. in: JCI | PubMed | Google Scholar
Published April 1, 1974 - More info
To gain further insight into the mechanism of action of cholera toxin, solubilized preparations of adenylate cyclase from control and toxin-treated rat livers were studied. Adenylate cyclase activity was measured in both particulate and solubilized form in rat liver under control conditions and after intravenous injection of cholera toxin. Cholera toxin caused a 3.3-fold activation of adenylate cyclase in the particulate preparation and a 5.8-fold increase in the solubilized preparation. Thus, the ability of cholera toxin to stimulate adenylate cyclase is present even when the enzyme membrane environment is disrupted. Furthermore, the solubilized enzyme, after treatment with cholera toxin, retained its ability to respond to catecholamines, but not to glucagon. In contrast, the control enzyme lost its responsiveness to catecholamines and glucagon after solubilization.
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