Detection and characterization of epidermal proteinases by polyacrylamide gel electrophoresis

Electrophoresis of cornified cell extracts of 2-day-old rats, using SDS polyacrylamide gels copolymerized with alpha-casein or gelatin with or without plasminogen, was performed. Both Tris-HCl buffer soluble protein and KSCN solubilized protein contained a number of hydrolases for alpha-casein and/or gelatin, but PA (mol. wts 57 and 50K) was found only in the KSCN extract. The pH dependency, substrate specificity and mol. wt of plasminogen-independent proteinases were comparatively determined and DFP inhibition tested. This simple technique helped to identify the presence of several proteinases and to characterize them in partially purified epidermal extracts.