Zhou G, Ho P S, van Holde K E
Department of Biochemistry and Biophysics, Oregon State University, Corvallis 97331.
Biophys J. 1989 Feb;55(2):275-80. doi: 10.1016/S0006-3495(89)82802-4.
Starting from the Monod-Wyman-Changeux (MWC) model (Monod, J., J. Wyman, and J. P. Changeux. 1965. J. Mol. Biol. 12:88-118), we obtain an analytical expression for the slope of the Hill plot at any ligand concentration. Furthermore, we derive an equation satisfied by the ligand concentration at the position of maximum slope. From these results, we derive a set of formulas which allow determination of the parameters of the MWC model (kR, C, and L) from the value of the Hill coefficient, nH, the ligand concentration at the position of maximum slope [( A]0), and the value of nu/(n-nu) at this point. We then outline procedures for utilizing these equations to provide a "best fit" of the MWC model to the experimental data, and to obtain a refined set of the parameters. Finally, we demonstrate the applicability of the technique by analysis of oxygen binding data for Octopus hemocyanin.
从莫诺-怀曼-尚热(MWC)模型(莫诺,J.,J. 怀曼,和 J. P. 尚热。1965 年。《分子生物学杂志》12:88 - 118)出发,我们得到了在任何配体浓度下希尔图斜率的解析表达式。此外,我们推导了在最大斜率位置处配体浓度所满足的一个方程。基于这些结果,我们推导出了一组公式,这些公式能够根据希尔系数(n_H)、最大斜率位置处的配体浓度([A]_0)以及该点处(\nu/(n - \nu))的值来确定 MWC 模型的参数((k_R)、(C)和(L))。然后我们概述了利用这些方程使 MWC 模型与实验数据实现“最佳拟合”并获得一组精确参数的步骤。最后,我们通过分析章鱼血蓝蛋白的氧结合数据来证明该技术的适用性。