The net electric charge of proteins. A comparison of determinations by Donnan potential measurements and by gel electrophoresis.
The net electric charge of proteins. A comparison of determinations by Donnan potential measurements and by gel electrophoresis.
复制标题
蛋白质的净电荷。
DOI：
10.1016/0304-4165(89)90122-0
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
M. Wolgast
中科院分区：
文献类型：
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作者：
G. Ojteg;P. Lundahl;M. Wolgast
我们比较了一种基于Donnan电势测量确定蛋白质净电荷的新方法，正如Öjteg，G.，Nygren，K.和Wolgast，M.(1987)Acta Physiol简要描述的那样。斯坎德。129、277-286，用常规方法用聚丙烯酰胺凝胶电泳法。这项新技术利用Donnan电势来确定净价，Donnan电势在半透膜上形成，将不渗透的蛋白质从与蛋白质溶液相同离子组成的周围浴液中分离出来。这种方法的优点除了它的简单性外，还在于它可以确定例如蛋白质在自由流体相中的电荷，并且浴液的pH和离子组成可以在很大范围内变化。当离子强度增加一倍时，Donnan电势降至原值的一半。通常必须使用1-10 mg·ml−-1的蛋白质浓度。应用Donnan电位法测定了一系列等电点不同的蛋白质的净电荷。测定值与凝胶电泳法测定的数据吻合较好。
We compare a new method for the determination of the net charge of proteins based on Donnan potential measurements, as described briefly byÖjteg, G., Nygren, K. and Wolgast, M. (1987) Acta Physiol. Scand. 129, 277–286, with a conventional method using polyacrylamide gel electrophoresis. The new technique utilizes the Donnan potential, which develops over a semipermeable membrane that separates the non-permeating protein from the surrounding bath of the same ionic composition as the protein solution, to determine the net valency. The advantages of this method, besides its simplicity, are that it can determine the charge of, e.g., a protein in a free-fluid phase and that the pH and ionic composition of the bathing fluid can be varied over a broad range. The Donnan potential decreased to half its original value when the ionic strength was doubled. Usually a protein concentration of 1–10 mg·ml−1must be used. The Donnan potential method was applied to determine the net charges of a series of proteins with different isoelectric points. The values showed close agreement with the data obtained by gel electrophoresis.