对人眼晶状体α－晶体蛋白聚集体的准弹性激光散射研究

QUASI-ELASTIC LIGHT SCATTERING STUDIES ON HUMAN α-CRYSTALLINE SOLUTION

以准弹性激光散射技术，研究了人眼晶状体内α－晶体蛋白聚集体的扩散系数和流体力学半径，以及其弥散性随温度和浓度的变化。所研究的α－晶体蛋白用分离的方法分别取自成人和胚胎眼晶状体。研究结果表明，人眼α－晶体蛋白在一定浓度和温度下可形成聚集体，且其聚集体半径随α－晶体蛋白的浓度近乎线性地增大，随温度的增加而变小。对α－晶体蛋白溶液（５０ｍｍｏｌ／Ｌ磷酸脂缓冲液）的弥散度分析表明，溶液中有两种不同粒径的散射体，除开α－晶体蛋白聚集体外，还有一种粒径约为１８．５ｎｍ的估计是α－晶体蛋白单体分子。由于α－晶体蛋白分子的变性聚集在人眼白内障的形成起着重要作用，故本研究的结果对于人眼白内障随年龄及温度变化的发展过程及其机理的认识具有指导意义。

By means of quasielastic light scattering tecnique, the diffusion coefficient and hydrodynamic radius of the aggregates in human α-crystalline solution were measured as functions of the concentration of α-crystallin and temperature.It is found that there are two kinds of scatterers in the solutions.The first kind with a radius about 18.5nm is believed to be the monomer of α-crystallin,the other kind with greater radius is believed to be the aggregate of α-crystallin.The radius of the aggregates increases linearly with the concentration of α-crystallin, but decreases with temperature.The difference between the aggregates in fetal and adult α-crystalline solutions shows that the radius of the aggregates also increases with age.