Modulation of enzymatic activity of human mast cell tryptase and chymase by protease inhibitors.
OBJECTIVE
To investigate the actions of protease inhibitors on the enzymatic activities of tryptase and chymase in similar experimental systems.


METHODS
Human lung tryptase and human skin chymase were purified by a similar procedure involving high salt extraction of tryptase, heparin agarose affinity chromatography, and S-200 Sephacryl gel filtration chromatography. Actions of protease inhibitors on tryptase and chymase activities were examined by enzyme assays.


RESULTS
The specific activities of tryptase and chymase were 2.1 kU/g protein and 4.9 kU/g protein, respectively. Both preparations showed a single diffuse band on SDS-PAGE. Among non-native protease inhibitors, N-(1-hydroxy-2-naphthoyl)-L- arginyl-L-prolinamide hydrochloride (HNAP), leupeptin, antipain, benzamidine, and protamine inhibited more than 90 % enzymatic activity of tryptase, whereas soy bean trypsin inhibitor (SBTI), Z-Ile-Glu-Pro-Phe-CO2Me (ZIGPPM) and chymostatin inhibited more than 95 % enzymatic activity of chymase. Native protease inhibitors alpha 1-antitrypsin and secretory leukocyte protease inhibitor (SLPI) inhibited more than 90 % enzymatic activity of chymase, but lactoferrin appeared to enhance chymase enzymatic activity. All the 3 inhibitors had weak inhibitory actions on tryptase.


CONCLUSIONS
The protease inhibitors tested had relatively good selectivity to either tryptase or chymase.
He
Shao-Heng
SH
Allergy and Inflammation Research Institute, Medical College of Shantou University, Shantou 515031, China. shaohenghe@hotmail.com
Chen
Pu
P
Chen
Han-Qiu
HQ
D053818:Chymases; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology; D008168:Lung / Q000166:cytology / Q000201:enzymology; D008407:Mast Cells / Q000187:drug effects* / Q000201:enzymology; D011480:Protease Inhibitors / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism*; D012867:Skin / Q000166:cytology / Q000201:enzymology; D053802:Tryptases; D000515:alpha 1-Antitrypsin / Q000494:pharmacology
D007976:Leupeptins; D011480:Protease Inhibitors; D000515:alpha 1-Antitrypsin; D012697:Serine Endopeptidases; D053818:Chymases; D053802:Tryptases; C032854:leupeptin