Epidermal growth factor receptor binding is not a simple one-step process.
Epidermal growth factor receptor binding is not a simple one-step process.
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发表时间：
1989-10
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通讯作者：
K. Mayo;M. Nunez;C. Burke;C. Starbuck;D. Lauffenburger;C. Savage
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作者：
K. Mayo;M. Nunez;C. Burke;C. Starbuck;D. Lauffenburger;C. Savage
在 4°C 下测量 125I 标记的小鼠表皮生长因子 (EGF) 与单层培养物中人成纤维细胞上的受体的结合动力学。初始结合率作为激素浓度的函数，可以分别估计简单的二态开关速率常数 1.2 x 10(6) M-1 s-1 和 4.9 x 10(-3) s-1。这些两种状态参数的计算机对长期动力学和平衡结合数据的拟合不充分，表明正在发生额外的过程。非线性平衡斯卡查德图和在平衡前时间绘制的瞬态“伪斯卡查德”图支持这样的观点：在受体结合期间至少发生了一个其他过程。 125I-EGF 受体解离动力学图是双相的，产生的速率常数为 1.5 x 10(-2) s-1 和 5.6 x 10(-5) s-1，两种组分的比例随 125I-EGF 初始孵育时间的变化而变化。应用三元复合物模型，假设结合的受体与细胞表面相互作用分子复合，对所有数据给出了令人满意的拟合。
The binding kinetics of 125I-labeled mouse epidermal growth factor (EGF) to receptors on human fibroblast cells in monolayer culture were measured at 4 degrees C. Initial binding rates as a function of hormone concentration allowed estimation of simple two-state on-off rate constants of 1.2 x 10(6) M-1 s-1 and 4.9 x 10(-3) s-1, respectively. These two-state parameters gave inadequate computer fits to long term kinetic and equilibrium-binding data, suggesting that an additional process(es) was occurring. Nonlinear equilibrium Scatchard plots and transient "pseudo-Scatchard" plots taken at pre-equilibrium times support the idea that at least one other process is occurring during receptor binding. 125I-EGF-receptor dissociation kinetic plots were biphasic, yielding rate constants of 1.5 x 10(-2) s-1 and 5.6 x 10(-5) s-1 with the ratio of the two components changing with the time of initial incubation with 125I-EGF. Application of a ternary complex model which assumed complexation of the bound receptor with a cell surface interaction molecule gave satisfactory fits to all data.