Behavior of a pyrene-labeled phospholipid in monolayers of dimyristoyl-L-α-phosphatidylcholine at the gas-water interface: A fluorescence quenching study

Abstract

The behavior of N-(1-pyrenesulfonyl)dipalmitoyl-L-α-phosphatidylethanolamine (pyrene-DPPE) embedded in dimyristoyl-L-α-phosphatidylcholine (DMPC) monolayers at the gas-water interface has been examined by surface pressure-area isotherm measurements and steady-state and time-resolved fluorescence spectroscopy. The pyrene moiety of pyrene-DPPE markedly alters the packing characteristics from those of the pure lipid DPPE, contributing significantly to the area per molecule. Steady-state fluorescence spectra showed monomer emission only, and a nonlinear increase in fluorescence intensity with concentration of pyrene-DPPE was observed, which can be attributed to oxygen quenching. Time-resolved fl..