Miscibility of lipoteichoic acid in dipalmitoylphosphatidylcholine studied by monofilm investigations and fluorescence microscopy.
The miscibility of the bacterial amphiphile lipoteichoic acid, a constituent of the cytoplasmic membrane of Gram-positive bacteria, in dipalmitoylphosphatidylcholine has been investigated by classic monofilm measurements and fluorescence microscopy at the air-water interface of monofilms obtained by spreading mixtures of both amphiphiles on a water subphase. The isotherms indicated miscibility of both lipids at concentrations up to 30 mol% lipoteichoic acid, whereas at higher concentrations immiscibility was detected. Increasing the lateral pressure over a certain value, lipoteichoic acid is squeezed out of the monofilm. By fluorescence microscopy the influence of lipoteichoic acid on the domain shape of condensed dipalmitoylphosphatidylcholine phases has been studied. The balance between hydrophobic and hydrophilic forces in the mixtures of both amphiphiles is discussed.
Gutberlet
T
T
Institut für Kristallographie der Freien Universität Berlin, Germany.
Milde
K
K
Bradaczek
H
H
Haas
H
H
Möhwald
H
H
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008070:Lipopolysaccharides / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry; D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D013211:Staphylococcus aureus / Q000737:chemistry; D013682:Teichoic Acids / Q000737:chemistry*
D008070:Lipopolysaccharides; D008563:Membrane Lipids; D008567:Membranes, Artificial; D013682:Teichoic Acids; D015060:1,2-Dipalmitoylphosphatidylcholine; C009900:lipoteichoic acid