1: Chem Phys Lipids  2002 Dec;120(1-2):57-74 

Membrane destabilization induced by beta-amyloid peptide 29-42: Importance of
the amino-terminus.

Mingeot-Leclercq MP, Lins L, Bensliman M, Van Bambeke F, Van Der Smissen P,
Peuvot J, Schanck A, Brasseur R.

Unite de Pharmacologie Cellulaire et Moleculaire, Universite Catholique de
Louvain, Avenue E. Mounier 73, Bt 7370, B-1200, Brussels, Belgium

Increasing evidence implicates interactions between Abeta-peptides and membrane
lipids in Alzheimer's disease. To gain insight into the potential role of the
free amino group of the N-terminus of Abeta29-42 fragment in these processes, we
have investigated the ability of Abeta29-42 unprotected and Abeta29-42
N-protected to interact with negatively-charged liposomes and have calculated
the interaction with membrane lipids by conformational analysis. Using vesicles
mimicking the composition of neuronal membranes, we show that both peptides have
a similar capacity to induce membrane fusion and permeabilization. The fusogenic
effect is related to the appearance of non-bilayer structures where isotropic
motions occur as shown by 31P and 2H NMR studies. The molecular modeling
calculations confirm the experimental observations and suggest that lipid
destabilization could be due to the ability of both peptides to adopt metastable
positions in the presence of lipids. In conclusion, the presence of a free or
protected (acetylated) amino group in the N-terminus of Abeta29-42 is therefore
probably not crucial for destabilizing properties of the C-terminal fragment of
Abeta peptides.

PMID: 12426076 [PubMed - in process]