Biochemical characterization of soluble phospholipase A2 from rheumatoid synovial fluid.
Radiolabeled E. coli, Phosphatidylethanolamine (PE) and Phosphatidylcholine (PC), were used to characterize the phospholipase A2 (PLA2) activity in synovial fluid (SF) from rheumatoid arthritis (RA) patients. Cell-free fractions of SF contain a PLA2 enzyme that preferentially releases [14C]oleic acid from E. coli, requires calcium and is optimally active at neutral pH. Purified PE, but not PC is also readily degraded by the soluble enzyme. A cell-associated PLA2 present in sonicates of SF mononuclear cells and neutrophils preferentially releases [3H]AA from E. coli. These studies suggest the presence of at least two different enzymes with activity of PLA2 in rheumatoid SF.
Gonzalez-Buritica
H
H
Department of Medicine, Section on Rheumatology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27103.
Smith
D M
DM
Turner
R A
RA
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001172:Arthritis, Rheumatoid / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism; D013379:Substrate Specificity; D013582:Synovial Fluid / Q000201:enzymology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D008823:Micelles; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D004492:Edetic Acid; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium