Involvement of a serine esterase in oxidant-mediated activation of phospholipase A2 in pulmonary endothelium.
Exposure of bovine pulmonary arterial endothelial cells to 1 mM H2O2 stimulated associated TAME-esterase and PLA2 activities. Pretreatment with the serine esterase inhibitors: PMSF (1 mM), DFP (1 mM), and alpha 1-PI (1 mg/ml) inhibited H2O2-induced stimulation of TAME-esterase and PLA2 activities. The TAME-esterase and PLA2 activities under H2O2 exposure were determined to be linearly correlated. Affinity labelling of the endothelial cell membrane with [3H]DFP demonstrated that the serine esterase resides in a protein having molecular weight of 29,000 daltons (29 kDa) which is similar to that of elastase. Treatment of the endothelial cell homogenate with trypsin (1 microgram/ml) also stimulated PLA2 activity.
Chakraborti
S
S
Department of Biochemistry and Biophysics, University of Kalyani, India.
Michael
J R
JR
D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000201:enzymology*; D004789:Enzyme Activation; D004950:Esterases / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D010447:Peptide Hydrolases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011651:Pulmonary Artery; D012044:Regression Analysis; D014357:Trypsin / Q000494:pharmacology
D004950:Esterases; C022635:serine esterase; D010741:Phospholipases A; D054467:Phospholipases A2; D010447:Peptide Hydrolases; C023073:tosylarginine methyl ester hydrolase; D014357:Trypsin