van den Berg B, Tessari M, Boelens R, Dijkman R, de Haas G H, Kaptein R, Verheij H M
Department of Enzymology and Protein Engineering, Utrecht University, The Netherlands.
Nat Struct Biol. 1995 May;2(5):402-6. doi: 10.1038/nsb0595-402.
It has long been proposed that the higher activity of phospholipase A2 (PLA2) for substrates presented as multimolecular aggregates compared to dispersed molecules (interfacial activation) arises due to a conformational change in the enzyme. X-ray studies have, however, failed to identify any such change. Here we report the solution structures of porcine pancreatic PLA2 both free and as a ternary complex with micelles and a competitive inhibitor. Important differences between these structures indicate that conformational changes may play an important role in the mechanism of interfacial activation in PLA2s.
