Probing the role of C-1 ester group in Naja naja phospholipase A2- phospholipid interactions using butanetriol-containing phosphatidylcholine analogues

Abstract

To understand the role of the ester mioety of the sn-1 acyl chain in phospolipase A2- glycerophospholipid interaction, we introduced an additional methylene residue between the glycerol CI and C2 carbon atoms of phosphatidylcholines, and then studies the kinetics of hydrolysis and the binding of such butanetriol-containing phospholipid with Naja phospholipase A2. Hydrolysis was monitored by using phospholipid containing a NBD-labelled sn-2 acyl chain and binding was ascertained by measuring the protein tryptophan fluorescence. The hydrolysis of butanetriol- containing phospholipids was invaribly slower than that of the glycerol-containing phospholipids. in addition, the enzyme binding with the substrate was merkedly decreased upon replacing the glycerol residue with the 1,3,4-butanetriol moiety in phosphatidylcholines. these results have been interpreted to suggest that the sn-1 ester group in glycerophospholipids chould play an important role in phospholipase A2- phospholipid interactions.