Rapid and sensitive assay of human plasma phospholipase A2 activity.

Phospholipase A2 (EC 3.1.1.4) can be determined with 14C-oleate labeled E. coli as substrate and with the use of a Millipore filter to separate the product of hydrolysis, i.e. the 14C-oleic acid, from the unhydrolyzed substrate. After incubation, the enzyme-substrate mixture is simply passed through a Millipore filter; the radioactivity in the filtrate then provides a sensitive and accurate measure of phospholipase A2 activity. The procedure is rapid and simple and can be used to determine the increased plasma levels of phospholipase A2 activity that may occur in human disease states.