Prediction of Hydrodynamic Parameters of Biopolymers from Small-Angle Scattering Data
Prediction of Hydrodynamic Parameters of Biopolymers from Small-Angle Scattering Data
复制标题
根据小角散射数据预测生物聚合物的流体动力学参数
DOI：
10.1107/s0021889897003336
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发表时间：
1997
影响因子：
6.1
通讯作者：
P. Zipper
中科院分区：
文献类型：
--
作者：
H. Durchschlag;P. Zipper
为了关联一些结构和流体动力学参数，生物聚合物被建模为长形或扁圆形的旋转椭球或球体（全身方法）。通过结合旋转半径与水化体积或表面体积比来估计轴向比。从这些轴比和其他参数（体积、摩尔质量、部分比容）中，可以推导出各种流体动力学量：摩擦比、沉降和扩散系数、西姆哈系数和固有粘度。此外，计算了几种等效球体的半径（与实验体积、扩散系数和固有粘度的实验或计算值有关），并将其与相应的旋转半径进行了比较。最后，验证了旋转半径与扩散系数或黏度半径、沉降系数与摩尔质量相关的简单经验方程的有效性。作为例子，考虑了不同摩尔质量和形状的各种球状生物聚合物（如蛋白质、病毒和核糖核酸）的结构和流体动力学性质。在不同技术和方法提供的观测值和预测值之间实现了深远的一致性；然而，对于某些情况（例如空心或不均匀颗粒），必须采用更复杂的程序。预测方法也被用于配体诱导的酶形状变化的流体动力学建模。详细阐述了一个代表性的例子，包括对误差的关键评估。
For correlating a number of structural and hydrodynamic parameters, biopolymers were modeled as prolate or oblate ellipsoids of revolution or as spheres (whole-body approaches). Axial ratios were estimated by combining the radius of gyration with either the hydrated volume or the surface-to-volume ratio. From these axial ratios and other parameters (volume, molar mass, partial specific volume), various hydrodynamic quantities were derived: frictional ratios, sedimentation and diffusion coefficients, Simha factors and intrinsic viscosities. In addition, the radii of several kinds of equivalent spheres (related to experimental volume and experimental or calculated values of diffusion coefficients and intrinsic viscosities) were computed and compared with each other and with the corresponding radii of gyration. Finally, the validity of simple empirical equations relating radius of gyration and diffusion coefficient or viscosity radius, sedimentation coefficient and molar mass was tested. As examples, the structural and hydrodynamic properties of a variety of globular biopolymers (such as proteins, viruses and ribonucleic acids) of different molar mass and shape were considered. Far-reaching conformity between observed and predicted values provided by the different techniques and approaches was achieved; for certain cases (e.g. hollow or inhomogeneous particles), however, more sophisticated procedures had to be applied. Predictive approaches were also used for hydrodynamic modeling of ligand-induced shape changes of enzymes. A representative example was elaborated in detail, including a critical assessment of errors.