Immunochemical and immunohistochemical studies on distribution of elastin fibres in human atherosclerotic lesions using a polyclonal antibody to elastin-derived hexapeptide repeat.

A polyclonal antibody to elastin-derived hexapeptide repeat, H-(Val-Gly-Val-Ala-Pro-Gly)(3)-NH(2), was prepared in order to investigate the differences between elastin fibres in intimal hyperplasia and media in human atheroscleroic lesions. The hexapeptide repeat and alpha-elastin were recognized by this polyclonal antibody in enzyme-linked immunosorbent assay (ELISA), but other elastin-derived peptides such as tetrapeptide repeat, pentapeptide repeat and nonapeptide were not. In the series of hexapeptide repeats, H-(VGVAPG)(n)-NH(2) where n is 1-7, the polyclonal antibody reacted strongly with oligomers (n = 3-7) and weakly with dimer (n = 2), but not with monomer (n = 1). CD measurements suggested that the beta-turn structure is important for recognition by the polyclonal antibody. In an immunohistochemical study, elastin was stained more strongly in intimal hyperplasia than in media, suggesting that newly synthesized elastin in intimal hyperplasia is morphologically distinct from that in media.