分子间相互作用对蛋白质晶体生长的影响

采用原子力显微镜对溶菌酶和刀豆蛋白A的分子间相互作用力的情况进行了研究, 并用动态光散射研究了此二种分子间相互作用力有较大差异的蛋白质在晶体生长条件和非生长条件下, 溶液中的聚集体的状态(大小和分散度)随浓度和温度的变化情况. 实验结果表明, 范德华力强的刀豆蛋白A在成核前, 溶液中的聚集体不能很快转变为生长基元, 导致晶体生长时间长; 而范德华力弱的溶菌酶, 溶液中的聚集体可以很快转变成生长基元, 晶体生长时间也较短.

Effect of Intermolecular Interaction on Protein Crystal Growth

The intermolecular interaction of lysozyme and concanavalin A were investigated by atomic force microscopy,respectively. The mean size and polydispersity of both lysozyme and concanavalin A ag-gregates in solution under crystallization and non-crystallization conditions as the function of protein con-centration and temperature were studied by dynamic light scattering method. The results showed that the in-termolecular interaction of protein molecules had a strong effect on nucleation during protein crystal growth. Because the van der Waals force among concanavalin A molecules was stronger than that among lysozyme molecules,the growth unit of concanavalin A crystal could not appear quickly after the precipitator was mixed with concanavalin A solution,which caused the longer crystal growth time than that for lysozyme.