Langmuir-Blodgett films of bipolar lipids from thermophilic archaea

The Langmuir-Blodgett technique is applied for depositing thin films of two lipids extracted from the thermophilic archaeon Sulfolobus Solfataricus as well as of a derivative produced by hydrolysis of total lipid extract. These are monosubstituted glycerol-dialkyl-nonitol tetraether with a β-d-glucopyranosyl group (GL-GDNT), bisubstituted glycerol-dialkyl-nonitol tetraether with β-d-glucopyranosyl and phosphomyoinositol groups (GL-GDNT-PH) and asymmetric non-substituted glycerol-dialkyl-nonitol tetraether (GDNT). Films with satisfactory morphology are deposited by both horizontal and vertical lift techniques, but the results are not reproducible. To improve the quality of deposition and the uniformity of the film, mixtures of the lipid GL-GDNT and arachidic acid are used. After dissolution of arachidic acid from the multilayer by hexane highly uniform films are obtained. Studies of the monolayers at the air-water interface and of the deposited films show that probably the molecules in the monolayer are in a form of a U with close packing of isopranyl chains.