Stephens R E
Biochim Biophys Acta. 1985 Dec 19;821(3):413-9. doi: 10.1016/0005-2736(85)90045-8.
When either membranes from scallop gill cilia or reconstituted membranes from the same source are solubilized with Triton X-114 and the detergent is condensed by warming, no significant fraction of any major membrane protein partitions into the micellar detergent. Rather, most of the membrane lipids condense with the detergent phase, forming mixed micelles from which nearly pure lipid vesicles may be produced by adsorption of detergent with polystyrene beads. One minor membrane protein, with a molecular weight of about 20 000, is associated consistently with these vesicles. The aqueous phase contains a fairly homogeneous protein-Triton X-114 micelle sedimenting at 2.6 S in the analytical ultracentrifuge. Sucrose gradient velocity analysis in a detergent-free gradient indicates moderate size polydispersity but constant polypeptide composition throughout the sedimenting protein zone. Sucrose gradient equilibrium analysis (also in a detergent-free gradient) results in a protein-detergent complex banding at a density of 1.245 g/cm3. Sedimentation of the protein-detergent complex in the ultracentrifuge, followed by fixation and normal processing for electron microscopy, reveals a fine, reticular material consisting of 5-10-nm granules. These data are consistent with previous evidence that membrane tubulin and most other membrane proteins exist together as a discrete lipid-protein complex in molluscan gill ciliary membranes.
当用Triton X-114溶解扇贝鳃纤毛的膜或相同来源的重构膜，并通过加热使去污剂浓缩时，任何主要膜蛋白都没有显著部分分配到胶束去污剂中。相反，大多数膜脂与去污剂相浓缩，形成混合胶束，通过用聚苯乙烯珠吸附去污剂，可以从中产生几乎纯的脂质囊泡。一种分子量约为20000的次要膜蛋白始终与这些囊泡相关联。水相含有在分析超速离心机中以2.6 S沉降的相当均匀的蛋白质-Triton X-114胶束。在无去污剂梯度中的蔗糖梯度速度分析表明，在整个沉降蛋白区中，大小多分散性适中，但多肽组成恒定。蔗糖梯度平衡分析（同样在无去污剂梯度中）导致蛋白质-去污剂复合物在密度为1.245 g/cm3处形成条带。蛋白质-去污剂复合物在超速离心机中的沉降，随后进行固定和常规电子显微镜处理，揭示了一种由5-10纳米颗粒组成的精细网状物质。这些数据与先前的证据一致，即膜微管蛋白和大多数其他膜蛋白在软体动物鳃纤毛膜中作为离散的脂蛋白复合物共同存在。
