Thoenges Detlef, Zscherp Christian, Grell Ernst, Barth Andreas
Institut für Biophysik, Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7/Haus 74, 60590 Frankfurt/Main, Germany.
Biopolymers. 2002;67(4-5):271-4. doi: 10.1002/bip.10108.
In the case of the integral membrane protein Na+/K+-ATPase, preparation of highly concentrated samples for IR difference spectroscopy often leads to inactivation of the enzyme. Therefore, we compared the activity of Na+/K+-ATPase using different techniques of sample preparation. The loss of activity can be minimized by cooling the sample to 10 degrees C and by the addition of glycerol and dithiothreitol. The activity of Na+/K+-ATPase isolated from pig kidney is independent of the protein concentration whereas the enzyme from shark rectal gland is inactivated at concentrations above 1 microg/microL and is thus unsuitable for IR experiments.
就整合膜蛋白钠钾ATP酶而言，制备用于红外差示光谱的高浓度样品常常会导致该酶失活。因此，我们使用不同的样品制备技术比较了钠钾ATP酶的活性。通过将样品冷却至10摄氏度并添加甘油和二硫苏糖醇，可以将活性损失降至最低。从猪肾中分离出的钠钾ATP酶的活性与蛋白质浓度无关，而从鲨鱼直肠腺中提取的该酶在浓度高于1微克/微升时会失活，因此不适合用于红外实验。
