Lorber B, Bishop J B, DeLucas L J
Center for Macromolecular Crystallography, University of Alabama, Birmingham.
Biochim Biophys Acta. 1990 Apr 13;1023(2):254-65. doi: 10.1016/0005-2736(90)90421-j.
The commercial non-ionic detergent octyl beta-D-glucopyranoside is often contaminated by significant amounts of UV absorbing and/or ionic compounds that can associate with membrane proteins. Such impurities can be monitored by several techniques (i.e., spectrophotometry, size exclusion chromatography, and pH, conductivity, and surface tension measurements) and can be removed using mixed-bed ion exchange chromatography. High performance size exclusion chromatography, dynamic light scattering, and ultracentrifugation have been used to re-estimate the size of micelles of octyl beta-D-glucopyranoside since previously published data varied over a wide range. Aggregation numbers were 27 to 100 for micellar molecular weights 8000 to 29,000. Direct physical methods that do not perturbate the sample indicated a large size for the micelles (hydrodynamic radius 23 +/- 3 A; Mr 22,000 +/- 3000; aggregation number 75 +/- 10 for a 34 mM aqueous solution). In contrast the chromatographic micellar size appeared to be smaller (hydrodynamic radius 15 +/- 1 A; Mr 8000 +/- 1000; aggregation number 27). This underestimation may be the result of adsorption and/or alteration of the micelles.
商业化的非离子洗涤剂β-D-吡喃葡萄糖苷辛酯常被大量可与膜蛋白结合的紫外线吸收性和/或离子性化合物污染。这些杂质可用多种技术进行监测（如分光光度法、尺寸排阻色谱法以及pH、电导率和表面张力测量），并可通过混合床离子交换色谱法去除。由于先前发表的数据差异很大，因此已使用高效尺寸排阻色谱法、动态光散射法和超速离心法重新估算β-D-吡喃葡萄糖苷辛酯胶束的大小。胶束分子量为8000至29000时，聚集数为27至100。不干扰样品的直接物理方法表明胶束尺寸较大（对于34 mM的水溶液，流体力学半径为23±3 Å；分子量为22000±3000；聚集数为75±10）。相比之下，色谱法测得的胶束尺寸似乎较小（流体力学半径为15±1 Å；分子量为8000±1000；聚集数为27）。这种低估可能是胶束吸附和/或改变的结果。
