Identification of Multiple Tropoelastins Secreted by Bovine

High resolution gradient sodium dodecyl sulfate-pol-yacrylamide gel electrophoresis, cell-free translation, and elastin-specific antibodies were used to identify three tropoelastin isoforms secreted by bovine tissue and cells. Tropoelastin isolated from nuchal ligament and from conditioned culture medium or cell-matrix extracts of ligament fibroblasts and auricular chondro-cytes resolved as three distinct bands on sodium dode-cy1 sulfate-polyacrylamide gel electrophoresis with molecular weights of approximately 67,500 (tropoe-lastin I), 65,000 (tropoelastin 11), and 62,000 (tropoe-lastin 111). Three tropoelastin polypeptides with molec-ular mass 2-3 kDa higher than their corresponding tissue forms were also evident in cell-free translation products of ligamentum nuchae RNA, suggesting tha