Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8725, USA.
Biochemistry. 2009 Dec 15;48(49):11606-8. doi: 10.1021/bi9018708.
Bolaamphiphile-class surfactants composed of two hydrophilic (maltoside) headgroups connected by long saturated alkyl chains were tested for their ability to stabilize a solubilized membrane protein, Escherichia coli diacylglycerol kinase (DAGK), and to sustain its native function. Members of this "Bis-MALT-C(18-28)" series were poor solubilizers of DAGK in the absence of conventional detergent. However, mixed micelles of the bolaamphiphiles with either dodecylphosphocholine or beta-n-decyl maltoside were more effective and enhanced DAGK's thermal stability relative to corresponding detergent-only conditions. Moreover, certain bolaamphiphiles were seen to be lipidlike by providing partial activation of DAGK's catalytic activity. Finally, addition of bolaamphiphiles to micellar NMR samples of DAGK did not result in a degradation of spectral quality, indicating their compatibility with high-resolution structural studies. To the best of our knowledge, this work represents the first documentation of the potential of bolaamphiphile-class surfactants for use in biochemical and biophysical studies of MPs.
由两个亲水（麦芽糖）头基通过长饱和烷基链连接而成的两亲分子胶束类表面活性剂，用于测试其稳定溶解膜蛋白、大肠杆菌二酰基甘油激酶（DAGK）的能力，并维持其天然功能。该“Bis-MALT-C（18-28）”系列成员在没有常规去污剂的情况下，对 DAGK 的溶解能力较差。然而，两亲分子胶束与十二烷基磷酸胆碱或β-正癸基麦芽糖的混合胶束更有效，并相对于仅用去污剂的条件增强了 DAGK 的热稳定性。此外，某些两亲分子胶束通过提供 DAGK 催化活性的部分激活而表现出类脂性质。最后，向 DAGK 的胶束 NMR 样品中添加两亲分子胶束不会导致光谱质量下降，表明它们与高分辨率结构研究兼容。据我们所知，这项工作首次证明了两亲分子胶束类表面活性剂在 MPs 的生化和生物物理研究中的潜在用途。
