title: Effect of human mast cell tryptase on human plasma proenzymes.
abstract: The effect of human skin mast cell tryptase on human plasma proenzymes (prothrombin, coagulation factor XII, complement C1s, protein C and plasminogen) was investigated. Tryptase had no effect on these proenzymes, when incubated with them at 37 degrees C for up to 90 min, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by the ability to hydrolyze specific peptide p-nitroanilide substrates. After prolonged treatment with tryptase, proenzymes could be fully activated with their specific activators. The results indicate that tryptase neither activates these plasma proenzymes nor inactivates the corresponding active enzymes. As a positive control, the tryptase preparation was also incubated with human fibrinogen and rat thymus histones. Prolonged treatment with tryptase increased the thrombin-induced clotting time of fibrinogen. Tryptase also efficiently hydrolyzed histone H1 from rat thymus. Histones H3/H2B and H2A were hydrolyzed less efficiently than H1, and no hydrolysis of histone H4 by tryptase was detected under the experimental conditions.
authors.affiliation: Department of Dermatology, University of Kuopio, Finland.
authors.forename: I T
authors.initials: IT
authors.lastname: Harvima
authors.forename: R J
authors.initials: RJ
authors.lastname: Harvima
authors.forename: I M
authors.initials: IM
authors.lastname: Penttilä
authors.forename: T O
authors.initials: TO
authors.lastname: Eloranta
authors.forename: M
authors.initials: M
authors.lastname: Horsmanheimo
authors.forename: J E
authors.initials: JE
authors.lastname: Fräki
mesh_terms: D000818:Animals; D003173:Complement C1s / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004792:Enzyme Precursors / Q000097:blood*; D005174:Factor XII / Q000378:metabolism; D005341:Fibrinolysin / Q000097:blood; D006801:Humans; D008407:Mast Cells / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000502:physiology*; D011486:Protein C / Q000378:metabolism; D011516:Prothrombin / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012867:Skin / Q000201:enzymology; D013917:Thrombin / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D011486:Protein C; D011516:Prothrombin; D005174:Factor XII; D010447:Peptide Hydrolases; C023073:tosylarginine methyl ester hydrolase; D003173:Complement C1s; D013917:Thrombin; D005341:Fibrinolysin