Kaiushina R L, Izotova T D, Mogilevskiĭ L Iu, Shmakova F V, Khurgin Iu I
Bioorg Khim. 1985 Jun;11(6):753-61.
The data of small-angle X-ray scattering from monoclonal immunoglobulin MCep (IgM) enabled the shape and geometrical parameters of the molecule in solution at 23 degrees C to be established. The molecule is a flat, strongly anisometric particle with radius of gyration 115 A, volume 1,8 X 10(6) A3, maximum size 380 A, thickness 35-40 A. The most probable molecular model in the approximation of homogeneous electron density in the molecule was suggested, its geometry fitting the experimental parameters. The five IgM subunits are located in the equatorial plane, low-electronic-density regions are located in the centre and at the periphery of the macromolecule. In addition, the absence of fixed angle values between Fab-regions in each subunit is indicative of rather high structural mobility at the periphery of the IgM molecule.
单克隆免疫球蛋白MCep（IgM）的小角X射线散射数据能够确定该分子在23摄氏度溶液中的形状和几何参数。该分子是一个扁平的、高度各向异性的粒子，回转半径为115埃，体积为1.8×10⁶埃³，最大尺寸为380埃，厚度为35 - 40埃。提出了分子中电子密度均匀近似下最可能的分子模型，其几何形状符合实验参数。五个IgM亚基位于赤道平面，低电子密度区域位于大分子的中心和外围。此外，每个亚基中Fab区域之间没有固定的角度值，这表明IgM分子外围具有相当高的结构灵活性。
