Neutral proteinase of rabbit skin: An enzyme capable of degrading skin protein and inducing an inflammatory response

1. 1. A neutral proteinase has been extracted from rabbit skin in the presence of 1 M KCl and purified 86-fold. 2. 2. The enzyme was active at neutral pH; it was not inhibited by diisopropylphosphorofluoridate, thiol-blocking reagents or EDTA. 3. 3. About 85% of the activity in skin was located in the dermis, the remainder in the epidermis. 4. 4. Incubation of skin with enzyme resulted in the release of trichloroacetic acid-soluble peptides from the tissue. 5. 5. Intradermal injection of the purified neutral proteinase into rabbits produced whealing within 15 min and acute leukocytic infiltration within 18 h. It is suggested that this enzyme may play a part in the initiation of an inflammatory reaction in skin.