Human C-apolipoproteins promote hydrolysis of dimyristoyl phosphatidylcholine by snake venom phospholipase A2

Introduction Lipoprotein lipase, the enzyme which metabolizes triglyceride-rich plasma lipoproteins, is activated by apolipoprotein CII [ 11. That this activation is impor- tant for the physiological action of the enzyme is demonstrated by the massive hypertriglyceridemia in patients deficient in this apolipoprotein [2]. Whereas the activation of lipoprotein lipase by CII appears to be a specific effect and probably involves direct pro- tein-protein interaction, there are also reports that other apolipoproteins activate or inhibit lipoprotein lipase [3-l l] and/or the related heparin heparin- releasable lipase