Interaction of immobilized betulinic acid and phospholipase A2

[[abstract]]Betulinic acid (BA), a triterpenoid of white birch (Betula alba), exhibits anti-viral, anti-malarial, anti-tumor and anti-inflammatory activities. Although it has been shown to be an inhibitor of bovine pancreatic phospholipase 2 (bp-PLA2), the identity of its cellular targets remain uncertain. We found that BA could inhibit bp-PLA2 enzymatic activity and cytotoxicity of N-PLA2 (PLA2 of Naja nigricollis). The interaction between BA and the PLA2 seemed to be mediated by electrostatic interaction and hydrophobic interaction. As an effort of identifying the cellular target of BA, the BA immobilized matrix was made and the utility of the immobilized column was studied. As expected, the BA-immobilized column exhibited a strong affinity with bp-PLA2 or N-PLA2. Surprisingly, the column also binds cardiotoxin c, which does not resemble to PLA2 in tertiary structure. Thus, BA-immobilized affinity column appears to be useful to explore the cellular targets of BA.[[fileno]]2050123030001[[department]]生科