Probing the role of substrate conformation in phospholipase A sub(2) action on aggregated phospholipids using constrained phosphatidylcholine analogues

Phospholipase A sub(2)s hydrolyze aggregated phospholipid substrates much more rapidly than dispersed monomeric ones. Whether this is a consequence of interface-associated conformational changes of the enzyme or of the substrate, or of both, remains a key question in lipid enzymology. The results strongly support the contention that specific packing-induced conformations of aggregated substrate play a substantial role in the large interfacial activations observed with phospholipase A sub(2).