Cherniak V Ia, Magretova N N
Mol Biol (Mosk). 1980 Mar-Apr;14(2):330-7.
The theory underlying the autocalibration method of sedimentation equilibrium for ideal solutions and its experimental verification for isolated proteins and a mixture of two proteins are described. The method is based on simultaneous calculation of an invisible base level yg which is to be known for calibration of sedimentation equilibrium patterns and parameter q = M (1--upsilon rho) omega 2/RT. It is shown that owing to this "autocalibration" the accuracy of molecular weight measurements increases to about 1% for homogeneous proteins and to 3--4% for mixtures of two proteins. Thus there is no need either in "meniscus depletion" as in the case of a "high speed" equilibrium method, or in determination of C0 and solute preservation in the cell ("low speed" method). The speed may be so low that the optical distortions would be minimized, the initial concentration may be varied over a wide range from approximately 0.1 mg/ml and higher (with interference optics). The autocalibration method allows one to repeat the calculations on intervals truncated from the bottom and from the meniscus, which ensures a good estimation of the homogeneity of the solution.
描述了理想溶液沉降平衡自动校准方法的基本理论及其对分离蛋白质和两种蛋白质混合物的实验验证。该方法基于同时计算一个不可见的基线水平yg，这是校准沉降平衡模式所必需的，以及参数q = M (1 - υρ)ω²/RT。结果表明，由于这种“自动校准”，对于均质蛋白质，分子量测量的精度提高到约1%，对于两种蛋白质的混合物，精度提高到3 - 4%。因此，既不需要像“高速”平衡法那样进行“弯月面耗尽”，也不需要测定C0和细胞中溶质的保留情况（“低速”法）。速度可以非常低，以至于光学畸变将最小化，初始浓度可以在很宽的范围内变化，从大约0.1 mg/ml及更高（采用干涉光学）。自动校准方法允许在从底部和弯月面截断的区间上重复计算，这确保了对溶液均匀性的良好估计。
