Mullin B R, Aloj S M, Fishman P H, Lee G, Kohn L D, Brady R O
Proc Natl Acad Sci U S A. 1976 May;73(5):1679-83. doi: 10.1073/pnas.73.5.1679.
Unlabeled cholera toxin inhibits [125I]thyrotropin binding to thyrotropin receptors on thyroid plasma membranes. Maximal inhibition by cholera toxin does not exceed 40%, whereas unalbeled thyrotropin completely inhibits [125I]thyrotropin binding to these same membranes. Kinetic analyses of the binding data are compatible with the view that the cholera toxin decreases the number of receptor sites available to thyrotropin and that the mechanism by which the cholera toxin inhibits [125I]thyrotropin binding to these receptor sites involves both competitive and noncompetitive elements.
未标记的霍乱毒素可抑制[125I]促甲状腺激素与甲状腺质膜上促甲状腺激素受体的结合。霍乱毒素的最大抑制率不超过40%,而未标记的促甲状腺激素则可完全抑制[125I]促甲状腺激素与这些相同质膜的结合。结合数据的动力学分析与以下观点相符:霍乱毒素可减少促甲状腺激素可利用的受体位点数量,且霍乱毒素抑制[125I]促甲状腺激素与这些受体位点结合的机制涉及竞争性和非竞争性因素。