Jürgens G, Knipping G M, Zipper P, Kayushina R, Degovics G, Laggner P
Biochemistry. 1981 May 26;20(11):3231-7. doi: 10.1021/bi00514a038.
Two subfractions of low-density lipoproteins (LDL) were isolated from normal pig (Sus domesticus) serum by a combined method including precipitation, ultracentrifugation, and gel chromatography. The fractions recovered from the buoyant density ranges 1.020-1.050 and 1.050-1.090 g/mL, denoted as LDL1 and LDL2, respectively, were studied with regard to structure and thermotropic behavior by X-ray small-angle scattering and were compared to human serum low-density lipoprotein of density 1.020-1.063 g/mL. The average molecular weights determined from the scattering intensities on absolute scale were 2.6 X 10(6) and 2.0 X 10(6) for LDL1 and LDL2, respectively. The maximum particle diameters were found to be 24 and 21 nm, respectively. Both species were found to have quasi-spherical symmetry and to display the thermotropic transition of the apolar lipids within the particle core similar to human LDL. The width of the transition was approximately 9 degrees C in both cases, but the midpoint transition temperature was higher by 8 degrees C for LDL1 (33 degrees C) than for LDL2 (25 degrees C). Despite their different sizes and thermotropic behavior, the two porcine LDL subfractions appear to be built according to the same structural principle as human LDL in the molecular organization of the apolar lipids within the particle core.
通过沉淀、超速离心和凝胶色谱相结合的方法，从正常猪（家猪）血清中分离出了两个低密度脂蛋白（LDL）亚组分。从浮力密度范围1.020 - 1.050和1.050 - 1.090 g/mL回收的组分，分别记为LDL1和LDL2，通过X射线小角散射研究了它们的结构和热致行为，并与密度为1.020 - 1.063 g/mL的人血清低密度脂蛋白进行了比较。根据绝对尺度上的散射强度确定的LDL1和LDL2的平均分子量分别为2.6×10⁶和2.0×10⁶。发现最大粒径分别为24和21 nm。两种物质均具有准球形对称性，并且颗粒核心内非极性脂质的热致转变与人类LDL相似。两种情况下转变宽度均约为9℃，但LDL1（33℃）的转变中点温度比LDL2（25℃）高8℃。尽管它们大小和热致行为不同，但在颗粒核心内非极性脂质的分子组织方面，这两种猪LDL亚组分似乎是按照与人类LDL相同的结构原理构建的。
