Effect of amyloid beta peptides Aβ1–28 and Aβ25–40 on model lipid membranes
- 227 Downloads
To investigate the molecular interaction of amyloid beta peptides Aβ1–28 or Aβ25–40 with model lipid membranes differential scanning calorimetry (DSC) and DPH and TMA DPH fluorescence anisotropy approaches were used. The main transition temperature (T m) and enthalpy change (ΔH) of model lipid membranes composed of DMPC/DPPG on addition of Aβ25–40 or Aβ25–40 at 10:1 (w/w) phospholipid/peptide ratio either non-aggregated or previously aggregated were examined. The effect of Aβ1–28 and Aβ25–40 on the membrane fluidity of liposomes made of DMPC/DPPG (98:2 w/w) was determined by fluorescence anisotropy of incorporated DPH and TMA DPH. The results of this study provide information that Aβ1–28 preferentially interacts with the hydrophilic part of the model membranes, while Aβ25–40 rather locates itself in the hydrophobic core of the bilayer where it reduces the order of the phospholipids packing.
KeywordsAmyloid beta peptides DMPC membrane DPH fluorescence anisotropy DSC
10 mM Hepes buffer pH-7.4
Differential scanning calorimetry
Main phase-transition enthalpy
Large unilamellar vesicles
Gel to liquid-crystalline phase transition temperature
1-[4-(trimethyl-ammonium) phenyl]- 6-phenyl-1,3,5-hexatriene
This work was supported by POL-POSTDOC III (PBZ/MniSW/07/2006/22) Nr D077/P01/2007, Ministry of Science and High education, Poland.
- 3.Revesz T, Ghiso J, Lashley T, Plant G, Rostagno A, Frangione B, et al. Cerebral amyloid angiopathies: a pathologic, biochemical, and genetic view. J Neuropathol Exp Neurol. 2003;62:885–98.Google Scholar
- 5.Serpell LC. Alzheimer’s amyloid fibrils: structure and assembly. Biochim Biophys Acta. 2000;1502:16–30.Google Scholar
- 9.Sabate R, Gallardo M, Estelrich J. Spontaneous incorporation in β-amyloid peptide into neutral liposomes. Colloids Surf. 2005;270(271):13–7.Google Scholar