UCLA

1. Elastin was isolated from the bulbus arteriosus of a salmonid fish. Monoclonal and polyclonal antibodies, elicited against a CNBr digest of this protein, immunoprecipitated a polypeptide of Mr 43,000 from fish cell culture medium. 2. Cell-free translation of salmon poly A+ RNA produced a protein of approximately 43 kD that was immunoprecipitated with anti-elastin antibodies. The corresponding mRNA had an approximate Mr of 2 kb. 3. Despite similarities in amino acid composition, the differences in Mr between mammalian and salmon mRNA and protein suggest a divergence of fish and higher vertebrate elastins from an earlier ancestral gene.