The antigenicity of soluble porcine elastins: I. Measurement of antibody by a radioimmunoassay.

Immunization of rabbits with either porcine tropoelastin, lung alpha-elastin, or aortic alpha-elastin resulted in the production of antibodies against the respective antigens. The assay of antibody activity with a radioimmunoassay indicated a high degree of cross reactivity between these three soluble elastin preparations. Through the use of competitive protein binding experiments it was possible to detect antigen-specific differences between tropoelastin and the two alpha-elastins. No antigenic differences were observed between lung or aortic alpha-elastin by any of the assay procedures uded in this investigation. Absorption of the various antisera with either insolubilized tropoelastin, lung elastin or aortic elastin allowed the preparation of non-crossreactive antibodies and provided further evidence for the antigenic differences between tropoelastin and the soluble alpha-elastins. The implications of the findings, as they relate to our current understanding of the molecular and structural arrangement of elastin and the elastin precursor, are discussed.