Minami H, Nylander T, Carlsson A, Larsson K
Department of Food Technology, University of Lund, Sweden.
Chem Phys Lipids. 1996 Jan 25;79(1):65-70. doi: 10.1016/0009-3084(95)02512-x.
Sphingomyelin from bovine milk and water form lipid gel phases at room temperature. A sample was used which incorporated of about 55% water, and X-ray diffraction data indicate an aqueous layer thickness of about 28 Angstrom. In order to accommodate proteins in the gel phase, the aqueous layer thickness was increased by solubilizing sodium palmitate into the sphingomyelin bilayer. In this way the gel phase could take up about 80% water. The incorporation of lysozyme, beta-lactoglobulin, and alpha-lactalbumin, was followed and the protein concentration for phase separation to occur was determined. It was found that the degree of incorporation was dependent on the salt concentration, thus the protein used was extensively dialysed. The amount of protein which can be dissolved in the thin aqueous layer of the gel phase was suggested to be limited by the dimensions of the layer. These are likely to be reduced as a consequence of the osmotic stress exerted by the 'outside' solution phase at high enough protein concentration.
来自牛乳的鞘磷脂与水在室温下形成脂质凝胶相。使用了一个含有约55%水的样品，X射线衍射数据表明水层厚度约为28埃。为了在凝胶相中容纳蛋白质，通过将棕榈酸钠溶解到鞘磷脂双分子层中来增加水层厚度。通过这种方式，凝胶相可以容纳约80%的水。跟踪了溶菌酶、β-乳球蛋白和α-乳白蛋白的掺入情况，并确定了发生相分离的蛋白质浓度。发现掺入程度取决于盐浓度，因此所用蛋白质经过了广泛透析。有人认为，能够溶解在凝胶相薄水层中的蛋白质数量受到该层尺寸的限制。在足够高的蛋白质浓度下，由于“外部”溶液相施加的渗透压力，这些尺寸可能会减小。
