Membranothropic properties of the urocanic acid

Abstract

The effects of urocanic acid (UA) on thermodynamic parameters of model dipalmitoylphosphatidylcholine (DPPC) lipid membrane have been studied by means of differential scanning calorimet­ry (DSC). The observed ordering effect of UA on the lipid bilayer is reflected in the increase in both the main phase transition temperature and cooperative unit size of the lipid membrane. Analysis of FTIR spectra suggests localization of UA molecules in the vicinity of the polar heads and carbonyl groups of DPPC due to electrostatic interactions and H-bonds. On the basis of experimental data obtained and geometry parameters of UA and DPPC molecules, some variants of the UA localization in DPPC bilayer were discussed.

Keywords

• differential scanning calorimetry
• dipalmitoylphosphatidylcholine
• FTIR spectroscopy
• multilamellar membrane
• urocanic acid