Zhou H X, Ferrone F A
Department of Physics and Atmospheric Science, Drexel University, Philadelphia, Pennsylvania 19104.
Biophys J. 1990 Sep;58(3):695-703. doi: 10.1016/S0006-3495(90)82412-7.
We have generalized the double nucleation mechanism of Ferrone et al. (Ferrone, F. A., J. Hofrichter, H. Sunshine, and W. A. Eaton. 1980. Biophys. J. 32:361-377; Ferrone, F. A., J. Hofrichter, and W. A. Eaton. 1985. J. Mol. Biol. 183:611-631) to describe the spatial dependence of the radial growth of polymer domains of sickle hemoglobin. Although this extended model requires the consideration of effects such as monomer diffusion, which are irrelevant to a spatially uniform description, no new adjustable parameters are required because diffusion constants are known independently. We find that monomer diffusion into the growing domain can keep the net unpolymerized monomer concentration approximately constant, and in that limit we present an analytic solution of the model. The model shows the features reported by Basak, S., F. A. Ferrone, and J. T. Wang (1988. Biophys J. 54:829-843) and provides a new means of determining the rate of polymer growth. When spatially integrated, the model exhibits the exponential growth seen in previous studies, although molecular parameters derived from analysis of the kinetics assuming uniformity must be modified in some cases to account for the spatially nonuniform growth. The model developed here can be easily adapted to any spatially dependent polymerization process.
我们推广了费罗内等人（费罗内，F.A.，J.霍夫里希特，H.桑夏恩，和W.A.伊顿。1980年。《生物物理杂志》32卷：361 - 377页；费罗内，F.A.，J.霍夫里希特，和W.A.伊顿。1985年。《分子生物学杂志》183卷：611 - 631页）的双成核机制，以描述镰状血红蛋白聚合物结构域径向生长的空间依赖性。尽管这个扩展模型需要考虑诸如单体扩散等效应，而这些效应在空间均匀描述中是无关的，但由于扩散常数是独立已知的，所以不需要新的可调参数。我们发现单体扩散到生长结构域中可以使未聚合单体的净浓度大致保持恒定，在此极限下我们给出了该模型的解析解。该模型展示了巴萨克、S.、F.A.费罗内和J.T.王（1988年。《生物物理杂志》54卷：829 - 843页）所报道的特征，并提供了一种确定聚合物生长速率的新方法。当进行空间积分时，该模型呈现出先前研究中所见的指数增长，尽管在某些情况下，从假设均匀性的动力学分析中得出的分子参数必须进行修改，以考虑空间非均匀生长。这里开发的模型可以很容易地适用于任何空间依赖性聚合过程。
