0000000000083165
AUTHOR
Klaus Ring
Influence of the Main Phospholipid (MPL) fromThermoplasma Acidophilumand of Liposomes from MPL on Living Cells: Cytotoxicity and Mutagenicity
AbstractLiposomes of the main phospholipid (MPL) from the archaebacterium Thermplasma acidophilum were investigated for their interference with living cells. Growth of mouse lymphoma cells L5178Y, permanent hamster fibroblasts V79, Ehrlich-mouse-ascites tumor (EMAT) cells and a variety of other celltypes was not influenced by these liposomes. Mutagenicity and antimutagenic efficacy were tested with Salmonella typhimurium TA100 in the “Ames plate-incorporation test”. No cytotoxicity and mutagenicity of liposomes from MPL was detected. The influence of MPL liposomes on ion transport, intracellular pH, electrolytes, membrane potential, energy metabolism, and the biosynthesis of proteins and nu…
Reconstitution of bacteriorhodopsin and ATP synthase from Micrococcus luteus into liposomes of the purified main tetraether lipid from Thermoplasma acidophilum: proton conductance and light-driven ATP synthesis.
The archaebacterium Thermoplasma acidophilum is cultivated at 59 degrees C in a medium containing sulfuric acid of pH 2. The purified bipolar membrane spanning main phospholipid (MPL) of this organism can be used to produce stable liposomes of 100-500 nm in diameter either using a French pressure cell detergent dialysis or sonication. Despite a potassium diffusion potential of 186 mV very low ionic permeability of sonicated MPL liposomes was measured using the potassium binding fluorescent indicator benzofuran isophthalate PBF1, which measures net K+ uptake. The latter also remained very low, in the presence of the K(+) ionophore valinomycin and palmitic acid. Addition of valinomycin and th…