Evidence for the existence of three chick lung tropoelastins

Three tropoelastin polypeptides are identified among the cell-free translation products of chick embryo lung mRNAs and organ cultures extracts. The tropoelastins are distinguished by one and two dimensional gel electrophoretic systems and are all immunoreactive with monospecific chick tropoelastin antiserum. The ratio of the three tropoelastins does not vary significantly between 10 and 16 days of lung embryogenesis. The third tropoelastin (c) is found to co-migrate with tropoelastin b on SDS-polyacrylamide gel electrophoresis but is visible after cyanogen bromide cleavage of reticulocyte lysate proteins. Immunoprecipitates from lung organ culture also contain tropoelastins a, b and c.