Molecular size of secreted and cell-associated plasminogen activators from cultured epidermal cells

Publisher Website
Google Scholar
Abstract
The molecular sizes of secreted and cell‐associated plasminogen activators from four cultured cell types were determined using an SDS‐PAGE technique in which plasminogen and casein were included during polymerization of the polyacrylamide gel. The major bands of plasminogen activators secreted by human neonatal epidermal cells, human adult epidermal cells and transformed human squamous cells migrated the same distance as the high molecular weight band of authentic urokinase, indicating that the apparent molecular weight of these plasminogen activators was approximately 55,000 daltons. Plasminogen activator extracted from normal adult human epidertnis also migrated with this major band of plasminogen activator, and a minor higher molecular weight band was also detected. In contrast, plasminogen activators secreted by transformed mouse squamous cells migrated between the high molecular weight band (∼ 55K) and the low molecular weight band of urokinase (∼ 32K), indicating that plasminogen activators of mouse epidermal cells differ from those of human epidermal cells. The mobility of the major bands of plasminogen activators detected in cell lysates of the four cell types was identical to that of secreted plasminogen activators.