Interaction of proteins with linear polyelectrolytes and spherical polyelectrolyte brushes in aqueous solution.
Interaction of proteins with linear polyelectrolytes and spherical polyelectrolyte brushes in aqueous solution.
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DOI：
10.1039/b609879g
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发表时间：
2006-11
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影响因子：
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通讯作者：
A. Wittemann;Matthias Ballauff
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文献类型：
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作者：
A. Wittemann;Matthias Ballauff
本文综述了近年来蛋白质与阴离子聚电解质在水溶液中相互作用的研究进展。来自文献的数据表明，蛋白质甚至在等电点的“错误侧”也可以与线性聚电解质形成可溶性复合物，也就是说，对于高于蛋白质的等电点的pH值，在该pH值下聚电解质和蛋白质带相同电荷。迄今为止发表的所有数据表明，这种类型的吸附随着离子强度的增加而变弱。如果将碳链接枝到固体表面上形成碳刷，则会发现更强的相互作用。这里它已被证明，球形刷组成的核心约。100 nm直径和长连接的双链在低离子强度下强烈吸附蛋白质（“聚电解质介导的蛋白质吸附”; PMPA）。在高离子强度下，几乎没有吸附发生在球形刷上。一个关键的比较自由的聚电解质和刷上获得的数据表明，这两种现象可以追溯到补丁的正电荷的表面上的蛋白质。此外，我们讨论了刷层内的Donnan压力的PMPA过程的驱动力。在这里，我们发现了一个很好的相关性，这表明在吸附过程中释放的抗衡离子是主要的驱动力。
We review recent experiments on the interaction of proteins with anionic polyelectrolytes in aqueous solution. Data from the literature demonstrate that proteins can form soluble complexes with linear polyelectrolytes even on the "wrong side" of the isoelectric point, that is, for pH values above the isoelectric point of the proteins under which the polyelectrolytes and the proteins are like-charged. All data published so far demonstrate that this type of adsorption becomes weaker with increasing ionic strength. A much stronger interaction is found if the polyelectrolyte chains are grafted onto solid surfaces to form polyelectrolyte brushes. Here it has been shown that spherical polyelectrolyte brushes consisting of a core of ca. 100 nm diameter and long attached polyelectrolyte chains strongly adsorb proteins at low ionic strength ("polyelectrolyte-mediated protein adsorption"; PMPA). Virtually no adsorption takes place onto the spherical polyelectrolyte brushes at high ionic strength. A critical comparison of data obtained on free polyelectrolytes and on polyelectrolyte brushes shows that both phenomena can be traced back to patches of positive charge on the surface of the proteins. Moreover, we discuss the driving force of the PMPA-process in terms of the Donnan pressure inside the brush layer. Here we find a good correlation which demonstrates that release of counterions during the process of adsorption is the main driving force.