Abstract
The structural characteristics of water molecules on membrane microproperties of L-α-phosphatidylcholines were investigated by a fluorescence spectrometer. Polarity in the surroundings of the hydrophilic groups of L-α-phosphatidylcholine molecules in gel and concentric lamella phases, using a static fluorescence technique, considerably changed at a water content of about 20 wt%, and microviscosity decreased with increasing water content. Addition of urea to L-α-phosphatidylcholine-water systems changed the polarity and microviscosity in the surroundings of hydrophilic groups at a water content above 20 wt% probably due to change of structural characteristics of interlamella water. The present study suggests that the physicochemical microproperties of L-α-phosphatidylcholine bilayer are related to the structural characteristics of water molecules.
