Products of epidermal protein synthesis

The products of epidermal protein synthesis in tissue slice and cell-free systems have been characterized by chromatographic, electrophoretic, and immunologic methods. Radiolabeled proteins of heterogeneous size are found in the supernatant and particulate fractions from both systems. The major labeled proteins in the supernatant fraction have molecular weights of approximately 43 000 and 65 000. The natively-insoluble proteins of the particulate fraction were solubilized either with desoxycholate or alkaline urea. Subsequent analysis of theses fractions yielded a labeled, high molecular weight, urea-soluble protein whose electrophoretic mobility was slower than that of the heavy chain of myosin. The immunologic reaction between the radiolabeled fraction and antibody raised against filamentous protein suggests that synthesis of proteins identical to epidermal filamentous protein occurs in the in vitro systems.