Shimura K, Kasai K
Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan.
Electrophoresis. 1989 Apr;10(4):238-42. doi: 10.1002/elps.1150100404.
The influence of a soluble anionic polymer on electrophoresis of proteins was studied in relation to the nonspecific ionic effect of an affinophore on application to affinophoresis. Zone electrophoresis of proteins was carried out in agarose gel in the presence of succinyl-poly-L-lysine (degree of polymerization, 120) by using three electrophoresis buffers differing in ionic strength (0.06, 0.12 and 0.18) and pH (7.0 and 7.9). Proteins migrated as distinct single bands even in the presence of the polymer. The mobility of cationic proteins towards the cathode was first decreased and then increased towards the anode as the polymer concentration increased, while that of anionic proteins was not affected. The dependence of the apparent mobility changes of the proteins on the concentration of the polymer was treated quantitatively in the same way as affinity electrophoresis. The extent of the ionic interaction between a cationic protein and the polymer could be estimated as an apparent dissociation constant. It greatly depended on the ionic strength of the electrophoresis buffer. Except for the extremely cationic proteins such as lysozyme, the ionic interaction with up to 0.1 mM of the polymer could be practically suppressed by the use of 0.1 M sodium phosphate buffer (pH 7.0).
研究了一种可溶性阴离子聚合物对蛋白质电泳的影响，这与亲和基团在亲和电泳应用中的非特异性离子效应相关。在琥珀酰 - 聚 -L-赖氨酸（聚合度为120）存在的情况下，通过使用三种离子强度（0.06、0.12和0.18）和pH值（7.0和7.9）不同的电泳缓冲液，在琼脂糖凝胶中进行蛋白质的区带电泳。即使在聚合物存在的情况下，蛋白质也迁移成明显的单带。随着聚合物浓度的增加，阳离子蛋白质向阴极的迁移率先降低，然后向阳极增加，而阴离子蛋白质的迁移率不受影响。蛋白质表观迁移率变化对聚合物浓度的依赖性与亲和电泳一样进行定量处理。阳离子蛋白质与聚合物之间离子相互作用的程度可以估计为表观解离常数。它很大程度上取决于电泳缓冲液的离子强度。除了如溶菌酶等极端阳离子蛋白质外，使用0.1 M磷酸钠缓冲液（pH 7.0）实际上可以抑制与高达0.1 mM聚合物的离子相互作用。
