Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
Electrophoresis. 2013 Jun;34(12):1812-9. doi: 10.1002/elps.201300050.
The influence of various cations as metal ions (barium, calcium, copper, magnesia, manganese, and nickel), pharmaceuticals (ephedrine, ethambutol, pilocarpine, and pirenzepine), arginine, and guanidine has been tested on BSA, β-lactoglobulin, and ovalbumin. Influences on proteins regarding changes in size, charge, or mass were of particular interest. ACE proved to be a suitable method to investigate these effects. ACE is able to observe slight but significant changes on proteins due to the excellent precision of the measurements. Therefore, some unexpected behaviors of protein-ligand interactions were found. The protein charge becomes more negative under metal ion influence and some pharmaceutical cations. Probably metal ions bound to the proteins form additional complexes with anions from the surrounding solution. Furthermore, already bound cations could be displaced at the protein surface. Both effects would change the overall charge of the ligand-protein complexes. In all studied cases, multiple-binding stoichiometries have been observed.
已经测试了各种阳离子（钡、钙、铜、氧化镁、锰和镍）、药物（麻黄碱、乙胺丁醇、毛果芸香碱和哌仑西平）、精氨酸和胍对 BSA、β-乳球蛋白和卵清蛋白的影响。特别关注对蛋白质大小、电荷或质量的影响。ACE 被证明是一种合适的方法来研究这些影响。ACE 能够观察到由于测量精度非常高而导致的蛋白质的微小但显著的变化。因此，发现了一些意想不到的蛋白质-配体相互作用行为。在金属离子和一些药物阳离子的影响下，蛋白质电荷变得更负。可能是与蛋白质结合的金属离子与来自周围溶液的阴离子形成额外的复合物。此外，已经结合的阳离子可以在蛋白质表面被取代。这两种效应都会改变配体-蛋白质复合物的总电荷。在所有研究的情况下，都观察到了多种结合化学计量。
