Proteolytic enzymes in human eccrine sweat: a screening study.

Thermally induced human eccrine sweat was collected both by simple scraping (SS) and by a polyethylene sweat collector that covered the Vaseline-coated skin of the back to minimize epidermal contamination (CS, clean sweat). Using synthetic chromogenic Kabi S-series substrates, we demonstrated a variety of proteases in both SS and CS, the former being higher than the latter to varying extents. The higher enzyme activity in SS is mainly due to epidermal contamination because abundant protease activity was eluted from the nonperspiring stripped and unstripped skin in vivo and from the stripped stratum corneum itself. The electrophoretic separation of sweat protein has shown that CS contains at least 7 and SS 15 gelatinolytic proteinases. Although some CS proteinases could be derived from the sweat duct, the sweat secretory coil itself is responsible for at least two proteinases at 78 and 25 kilodaltons. The identity and function of these enzymes remain to be studied.