A novel method for polypeptide design to prepare specific antibody of the peptide and applied to immunoassay

Peptide was polymerized by a novel method: compound containing double bond between two carbons such as acdryloyl chloride was introduced into peptide during peptide synthesis, then it was transformed to a polymer which has a poly propionyl core matrix with peptide branches by radical polymerization either after being cleaved from resin or before being cleaved from resin according to the peptide physical-chemical character. According to this design, the macromolecules with average MW about 40 kD for poly-Osteogenic Growth Peptide (poly-OGP), 25 KD for poly-penetratin could be produced. Poly-OGP was further applied for antibody preparation and immunoassays. Immunizing New Zealand rabbits, we obtained the antiserum with titer of 2.5x10(4), examined by enzyme-linked immunosorbent assay (ELISA), without cross-reaction with bovine serum albumin (BSA), while the antiserum produced by using BSA as peptide carrier strongly reacted with BSA (with titer of more than 50x10(4) for BSA). Based on competitive ELISA, the anti-poly-OGP antibody showed much better immunoreactive sensitivity than anti-BSA-OGP antibody by comparing their IC(50) toward OGP. The antigen determinant of OGP and the OGP content in the serum of mice, determined by anti-poly-OGP antibody, showed that the anti-polypeptide antibody can be used as tools for immunoassay. Thus, the polypeptide system is not only a new approach for preparing synthetic peptide antibody for immunoassays but also provided the prospect for preparing synthetic peptide-based vaccine.