title: Proteinases of human epidermis; a possible mechanism for polymorphonuclear leukocyte chemotaxis.
abstract: Three neutral proteinases (EC 3.4.--.--) and cathepsin D have been identified in human epidermis utilizing a highly sensitive radioactive method. The proteinases were extracted in 1.0 M KC1 and 0.1% Triton X-100 and separated by Sephadex G-75 chromatography. The neutral proteinase peaks were all inhibited by diisopropyl fluorophosphate and thus were serine proteinases. Incubation of the enzyme fractions with [3H] diisopropyl fluorophosphate followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the two larger molecular weight proteinases were enzyme mixtures. The small molecular weight [3H] diisopropyl fluorophosphate proteinase migrated as a single band. Injection of the small molecular weight neutral proteinase into rabbit skin produced a polymorphonuclear leukocyte infiltration and edema. The reaction was not observed with the diisopropyl fluorophosphate-inhibited enzyme fraction. The release of neutral proteinases may be one of the signal events in the epidermal inflammatory response.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002403:Cathepsins / Q000302:isolation & purification / Q000378:metabolism; D002634:Chemotaxis, Leukocyte; D003872:Dermatitis / Q000473:pathology; D006801:Humans; D007249:Inflammation; D009504:Neutrophils / Q000502:physiology*; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D012867:Skin / Q000201:enzymology*; D014357:Trypsin / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D002403:Cathepsins; D010447:Peptide Hydrolases; D014357:Trypsin