Berlin 2015 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 35: Membranes and vesicles II (joint BP/CPP)
BP 35.4: Vortrag
Mittwoch, 18. März 2015, 16:00–16:15, H 1028
Al3+ binding effects on lipid membrane structure — Hannah Wayment-Steele1, Sofia Svedhem2, Lewis E. Johnson3, Malkiat S. Johal1, Björn Agnarsson2, and •Angelika Kunze4 — 1Dept. of Chemistry, Pomona College, CA, USA — 2Dept. of Applied Physics, Chalmers Univ. of Technology, Göteborg, Sweden — 3Dept. of Chemistry, Univ. of Washington, Seattle, WA, USA — 4Inst. of Physical Chemistry, Univ. of Göttingen, Göttingen, Germany
Aluminum is found in daily life as a contaminant in food-contact articles as well as in medical and cosmetic products. However, the aluminum ion has been identified as a neurotoxin; several studies have suggested that increased Al3+ concentrations are correlated with increased risks for Alzheimer's disease. The toxicity of the Al3+ derives from structural changes induced in membranes upon binding; it increases membrane rigidity, facilitates vesicle fusion and rupture. However, the mechanisms for these processes are still not fully understood.
Here, we elucidate the effect of Al3+ ions on neutral and charged mixed supported lipid membranes (SLMs) using a variety of surface sensitive experimental techniques in combination with molecular dynamic (MD) simulations.
Our results show that Al3+ affects lipid packing, bilayer thickness, diffusivity as well as it does induce irreversible domain formation in a mixed bilayer. The observed effects for neutral SLMs are mostly reversible whilst the effects observed for mixed SLMs are mostly irreversible. Notably does MD simulations reveal that Al3+ changes the order parameter of the fatty acid chains.