Activation of human neutrophil protein kinase C in vitro by 1,2-isopropylidene-3-decanoyl-sn-glycerol (IpOCOC9)

Compound 1,2-isopropylidene-3-decanoyl-sn-glycerol (IpOCOC9) augments the phosphorylation in vitro of histone III-S and myelin basic protein (MBP) by a partially purified Ca2(+)- and phospholipid-dependent protein kinase activity (protein kinase C) from human polymorphonuclear leukocytes. IpOCOC9 can substitute for either Ca2+ and phosphatidylserine or for phorbol ester. The related compound decanoid acid cyclopentyl methylester (DACPME) is less effective than IpOCOC9 in this respect. These data lend support to the notion that the secretagogue activity of IpOCOC9 with respect to human basophil histamine release and neutrophil superoxide radical generation is due to protein kinase C activation.