Effect of ionic strength on two-dimensional streptavidin crystallization
Effect of ionic strength on two-dimensional streptavidin crystallization
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DOI：
10.1021/la026176r
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发表时间：
2003-03-04
期刊：
影响因子：
3.9
通讯作者：
Gast, AP
中科院分区：
文献类型：
--
作者：
Ratanabanangkoon, P;Gast, AP
我们研究了二维（2D）结晶链霉亲和素在低离子强度条件下。我们研究了在空气-水界面上的巨单层脂双层囊泡和脂单层上的晶体。与在高离子强度缓冲液中的2D结晶相反，在这些条件下的静电排斥有利于低密度C222晶型。尽管表面几何形状不同，但在巨囊泡上生长的晶体和在脂质单层上生长的晶体显示出相同的晶体结构和相似的结晶趋势。当结晶溶液的离子强度逐渐增加，在pH 4时，我们观察到从C222的过渡到更致密的P1空间群常见于高离子强度条件下，在此pH值。一个新的晶体结构出现在中间离子强度，说明静电排斥在这些有序过程中的作用。
We study two-dimensional (2D) crystallization of streptavidin under low ionic strength conditions. We investigate crystals on both giant unilamellar lipid bilayer vesicles and lipid monolayers at the air-water interface. In contrast to 2D crystallization in high ionic strength buffers, the electrostatic repulsions under these conditions favor the low density C222 crystal form. The crystals grown on giant vesicles and those on lipid monolayers show the same crystal structure and similar crystallization trends despite the difference in surface geometries. When the ionic strength of the crystallization solution is progressively increased at pH 4, we observe a transition from C222 to the denser P1 space group commonly seen in high ionic strength conditions at this pH. A new crystal structure appears at intermediate ionic strength, illustrating the role of electrostatic repulsions in these ordering processes.