EFFECT OF OZONATION PRODUCTS ON PHOSPHOLIPASE A(2) HYDROLYTIC ACTIVITY - USE OF BIS(1-HYDROXYHEPTYL)PEROXIDE AS A PRECURSOR OF THE OZONATION PRODUCT 1-HYDROXY-1-HYDROPEROXYHEPTANE

Bis(1-hydroxyheptyl)peroxide (BisC7) upon spontaneous hydrolysis affor ds the difficult-to-isolate ozonation product 1-hydroxy-1-hydroperoxyh eptane along with heptanal. PLA(2) hydrolytic activity is enhanced whe n the BisC7 hydrolysis products are incorporated in the membrane of 1- palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine liposomes, suggesting t hey cause a pronounced alteration in the bilayer packing order. Conver sely, inhibition is observed when PLA(2) is incubated with BisC7 hydro lytic products prior to incubation with the liposomes, suggesting that these products are capable of reacting with and modifying the enzyme when present in solution. (C) 1994 Academic Press, Inc.