Endo Y, Miyai K, Hata N, Ichihara K
Anal Biochem. 1984 Dec;143(2):249-55. doi: 10.1016/0003-2697(84)90660-2.
Immunoglobulin G (IgG) fractions prepared from three different batches of rabbit antihuman thyrotropin (hTSH) antisera were fractionated by agarose isoelectric focusing (IEF) in the pH ranges 3 to 10 and 5 to 8. Staining of protein in agarose gel after IEF showed that polyclonal IgG separated into more than 20 protein bands with isoelectric points (pIs) ranging from 6 to 9. The clonotype antibodies to hTSH were recovered from the fractions and subjected to radioimmunoassay for determination of the binding-affinity for hTSH and the cross-reactivity with human chorionic gonadotropin (hCG). The affinity constants of the antibodies recovered ranged from 6.4 X 10(9) M-1 to 3.1 X 10(10) M-1, and the cross-reactivities of the clonotype antibodies differed greatly. A good correlation was observed between the pIs of antibody molecules and their cross-reactivities: antibodies with higher pIs bound hCG more strongly than those with lower pIs. The correlation coefficients between the pIs and cross-reactivities were 0.83, 0.84, and 0.87 in three batches of antibody.
从三批不同的兔抗人促甲状腺激素（hTSH）抗血清中制备的免疫球蛋白G（IgG）组分，在pH值范围为3至10和5至8的条件下，通过琼脂糖等电聚焦（IEF）进行分级分离。IEF后对琼脂糖凝胶中的蛋白质进行染色显示，多克隆IgG分离成20多条蛋白带，其等电点（pI）范围为6至9。从这些组分中回收针对hTSH的克隆型抗体，并进行放射免疫测定，以确定其对hTSH的结合亲和力以及与人绒毛膜促性腺激素（hCG）的交叉反应性。回收抗体的亲和常数范围为6.4×10⁹ M⁻¹至3.1×10¹⁰ M⁻¹，克隆型抗体的交叉反应性差异很大。观察到抗体分子的pI与其交叉反应性之间存在良好的相关性：pI较高的抗体比pI较低的抗体与hCG的结合更强。三批抗体中pI与交叉反应性之间的相关系数分别为0.83、0.84和0.87。
