Influence of carbonyl groups on the interaction of PLA2 with lipid interphases

Abstract

It is known that phospholipase A2 (PLA2) hydrolyzes phosphatidylcholines (PC) producing lysophosphatidylcholine and fatty acids. The substrate of the enzymatic action is the sn2 acyl chain being Ca2+ ion an essential cofactor for the activation. Many data are available showing the influence of hydration and defects of the interphase on the hydrolysis mechanism. In this regard, it is well known that carbonyl groups (CO) is a hydration site promoting different organization of water and packing defects at the surface level. In this paper, the adsorption and activity of PLA2 on ester and ether PC was measured in order to evaluate the influence of CO as hydration site. This was accomplished evaluating the zeta potential changes and the concomitant hydrolytic products in the presence of Ca2+. A model based on FTIR-ATR analysis and docking studies, considers the formation of an enzyme complex with CO and PO groups and Ca2+.