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Role of Ca2+‐Dependent Metalloprotease‐2 in Stimulating Ca2+ATPase Activity Under Peroxynitrite Treatment in Bovine Pulmonary Artery Smooth Muscle Membrane
Author(s) -
Chakraborti Tapati,
Das Sudip,
Mandal Malay,
Mandal Amritlal,
Chakraborti Sajal
Publication year - 2002
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216540212337
Subject(s) - leupeptin , chemistry , pepstatin , biochemistry , peroxynitrite , protease , egta , superoxide , calcium , enzyme , organic chemistry
We have determined effect of the oxidant peroxynitrite (ONOO ‐) on Ca 2+ ‐dependent matrix metalloprotease‐2 (MMP‐2) activity and the role of the protease on Ca 2+ ATPase activity in bovine pulmonary vascular smooth muscle plasma membrane under ONOO ‐‐triggered conditions. The smooth muscle plasma membrane possesses a 72‐kDa protease activity in a gelatin‐containing zymogram. The 72‐kDa protease activity has been found to be inhibited by tissue inhibitor of metalloprotease‐2 (TIMP‐2), indicating that the protease is the matrix metalloprotease‐2 (MMP‐2). Treatment of the membrane suspension with ONOO ‐ caused stimulation of the MMP‐2 activity (as evidenced by 14 C‐gelatin degradation) and also increased Ca 2+ ATPase activity. The ONOO ‐‐triggered protease activity and the Ca 2+ ATPase activity were found to be inhibited by the antioxidants: vitamin E, thiourea, and mannitol. Pretreatment with catalase and superoxide dismutase did not significantly alter ONOO ‐‐stimulated MMP‐2 activity and Ca 2+ ATPase activity, indicating that peroxide and superoxide are not present in appreciable amount in ONOO ‐. Under both basal and ONOO ‐ triggered conditions, the MMP‐2 activity and the Ca 2+ ATPase activity were also inhibited by EGTA, 1:10‐phenanthroline, and TIMP‐2. However, the ONOO ‐‐stimulated MMP‐2 activity and the Ca 2+ ATPase activity were found to be insensitive to phenylmethylsulfonylfluoride, Bowman‐Birk inhibitor, chymostatin, leupeptin, antipain, N ‐ethylmaleimide, and pepstatin. These results suggest that ONOO ‐ caused stimulation of MMP‐2 activity and that the increased MMP‐2 activity subsequently played a pivotal role in stimulating Ca 2+ ATPase activity in bovine pulmonary vascular smooth muscle plasma membrane.