Corcia A, Schweitzer-Stenner R, Pecht I, Rivnay B
EMBO J. 1986 May;5(5):849-54. doi: 10.1002/j.1460-2075.1986.tb04294.x.
Electric conductance was studied across micropipette-supported planar lipid bilayers, reconstituted with IgE-Fc epsilon receptor and the cromolyn-binding protein (CBP) isolated from membranes of rat basophilic leukemia cells (RBL-2H3). Currents were observed following the addition of aggregating agents, specific for either of the two proteins. The results show that the two proteins are necessary and sufficient for the opening of cation channels. Both aggregation of Fc epsilon receptor via IgE with a specific antigen and of CBP by anti-CBP induce channels with similar conductances and open-time distributions. In the presence of 1.8 mM calcium, the most frequently observed channels have a conductance of 1-2 pS. At 100 mM calcium conductance increased to 4-5 pS. Channels induced by antigen were susceptible to blocking by the anti-allergic drug cromolyn. These results suggest that CBP acts as the core of the cation channel and that the channel conductance and open-time characteristics are independent of the mode of aggregation.
研究了通过微吸管支撑的平面脂质双层的电导，该双层由从大鼠嗜碱性白血病细胞（RBL - 2H3）膜中分离出的IgE - Fcε受体和色甘酸结合蛋白（CBP）重构而成。在添加对这两种蛋白质之一具有特异性的聚集剂后观察到电流。结果表明，这两种蛋白质对于阳离子通道的开放是必要且充分的。通过IgE与特异性抗原聚集Fcε受体以及通过抗CBP聚集CBP均可诱导出具有相似电导和开放时间分布的通道。在存在1.8 mM钙的情况下，最常观察到的通道电导为1 - 2 pS。在100 mM钙时，电导增加到4 - 5 pS。由抗原诱导的通道易被抗过敏药物色甘酸阻断。这些结果表明，CBP作为阳离子通道的核心，并且通道电导和开放时间特性与聚集方式无关。
