Effects of detergent β-octylglucoside and phosphate salt solutions on phase behavior of monoolein mesophases.
Effects of detergent β-octylglucoside and phosphate salt solutions on phase behavior of monoolein mesophases.
复制标题
洗涤剂β-辛基葡萄糖苷和磷酸盐溶液对单油酸中间相相行为的影响。
DOI：
10.1016/j.bpj.2013.09.009
复制
发表时间：
2013
影响因子：
3.4
通讯作者：
Kenis,PaulJA
中科院分区：
文献类型：
--
作者：
Khvostichenko,DariaS;Ng,JohnathanJD;Perry,SarahL;Menon,Monisha;Kenis,PaulJA
利用小角x射线散射（SAXS）技术，研究了单油素（MO）与脂质中间相中膜蛋白结晶常用的添加剂混合后的相行为。特别是，我们研究了磷酸钠和磷酸钾盐以及清洁剂β-辛基葡萄糖苷（βOG）对脂质中间期膜蛋白结晶相关的广泛成分的影响。我们研究了两种类型的体系：1)水化边界以上的MO与盐溶液的三元混合物；2) MO与β og和盐溶液的四元混合物，在广泛的水化条件下。所有四元混合物均表现出高度规则的溶变相行为，在相似温度下，其相序列（Lα、i3d和pn3m）与MO/water混合物相同。添加剂在四元体系中的作用与只存在一种添加剂的三元混合物中的作用在质量上一致。然而，添加剂对完全水化中间相晶格参数的影响在三元和四元混合物之间存在定量差异。我们讨论了这些发现对脂质中间相膜蛋白结晶机理研究的意义，以及对中间相结晶方法中沉淀剂适用性研究的意义。
Using small-angle x-ray scattering (SAXS), we investigated the phase behavior of mesophases of monoolein (MO) mixed with additives commonly used for the crystallization of membrane proteins from lipidic mesophases. In particular, we examined the effect of sodium and potassium phosphate salts and the detergentβ-octylglucoside (βOG) over a wide range of compositions relevant for the crystallization of membrane proteins in lipidic mesophases. We studied two types of systems: 1), ternary mixtures of MO with salt solutions above the hydration boundary; and 2), quaternary mixtures of MO withβOG and salt solutions over a wide range of hydration conditions. All quaternary mixtures showed highly regular lyotropic phase behavior with the same sequence of phases (Lα,Ia3d, andPn3m) as MO/water mixtures at similar temperatures. The effects of additives in quaternary systems agreed qualitatively with those found in ternary mixtures in which only one additive is present. However, quantitative differences in the effects of additives on the lattice parameters of fully hydrated mesophases were found between ternary and quaternary mixtures. We discuss the implications of these findings for mechanistic investigations of membrane protein crystallization in lipidic mesophases and for studies of the suitability of precipitants for mesophase-based crystallization methods.