Fractionation of polyclonal antibody by isoelectric focusing--differences in cross-reactivity and affinity of rabbit clonotype anti-human thyrotropin antibody |
| |
Authors: | Y Endo K Miyai N Hata K Ichihara |
| |
Institution: | 1. Department of Laboratory Medicine, Osaka University Medical School, 1-1-50 Fukushima, Fukushima-ku, Osaka 553, Japan;2. Central Laboratory for Clinical Investigation, Osaka University Medical School, 1-1-50 Fukushima, Fukushima-ku, Osaka 553, Japan |
| |
Abstract: | 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. |
| |
Keywords: | isoelectric focusing radioimmunoassay anti-human thyrotropin antibody cross-reactivity rabbit IgG human thyrotropin (hTSH) |
本文献已被 ScienceDirect 等数据库收录! |
|