Sweet tastants stimulate adenylate cyclase coupled to GTP-binding protein in rat tongue membranes.
Sweet tastants stimulate adenylate cyclase coupled to GTP-binding protein in rat tongue membranes.
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DOI：
10.1042/bj2600121
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发表时间：
1989-05
期刊：
影响因子：
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通讯作者：
B. J. Striem;U. Pace;Uri Zehavi;Michael Naim;D. Lancet
中科院分区：
文献类型：
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作者：
B. J. Striem;U. Pace;Uri Zehavi;Michael Naim;D. Lancet
蔗糖和其他能使大鼠产生吸引人的味道的甜味剂被发现能显著刺激大鼠舌前背区膜中腺苷酸环化酶的活性。在来自舌肌或舌非感觉上皮的对照膜中，糖对腺苷酸环化酶活性的影响要小得多或不存在。蔗糖增强腺苷酸环化酶活性的剂量相关的方式，这种激活依赖于鸟嘌呤核苷酸的存在下，这表明参与的GTP结合蛋白（“G蛋白”）。腺苷酸环化酶的激活与各种单和双腺苷酸的电生理效能相关。在非糖甜味剂中，糖精钠激活了酶，而糖精钠和新橙皮苷二氢查耳酮则没有，这与它们在大鼠中的甜味效果有关。蔗糖激活的酶被部分抑制由Cu 2+和Zn 2+，在协议的电生理甜味反应的影响。我们的研究结果是一致的甜味转导机制，涉及特定的受体，鸟嘌呤核苷酸结合蛋白和环AMP产生酶腺苷酸环化酶。
Sucrose and other saccharides, which produce an appealing taste in rats, were found to significantly stimulate the activity of adenylate cyclase in membranes derived from the anterior-dorsal region of rat tongue. In control membranes derived from either tongue muscle or tongue non-sensory epithelium, the effect of sugars on adenylate cyclase activity was either much smaller or absent. Sucrose enhanced adenylate cyclase activity in a dose-related manner, and this activation was dependent on the presence of guanine nucleotides, suggesting the involvement of a GTP-binding protein ('G-protein'). The activation of adenylate cyclase by various mono- and di-saccharides correlated with their electrophysiological potency. Among non-sugar sweeteners, sodium saccharin activated the enzyme, whereas aspartame and neohesperidin dihydrochalcone did not, in correlation with their sweet-taste effectiveness in the rat. Sucrose activation of the enzyme was partly inhibited by Cu2+ and Zn2+, in agreement with their effect on electrophysiological sweet-taste responses. Our results are consistent with a sweet-taste transduction mechanism involving specific receptors, a guanine-nucleotide-binding protein and the cyclic AMP-generating enzyme adenylate cyclase.