The immunoreactive profile at the N-terminal region of A beta 1-39/40 but not A beta 1-42 changes with transition from monomer/dimer to further peptide aggregates.
Using site-specific antibodies, we assessed the effect of aggregation of various length forms of A beta on the immunoreactive profile of the peptides. All of the antibodies tested reacted with monomeric/dimeric forms of A beta 1-42 and its further aggregates. However, antibodies directed against the 1-24 region of A beta reacted weakly or not at all with A beta 1-39/40 monomers or dimers, but immunoreactivity was enhanced substantially following peptide incubation and aggregation. These results suggest that the conformation of the N-terminal region of monomeric and dimeric A beta 1-39/40 is different from that of aggregated forms, whereas the longer A beta 1-42 does not significantly change its N-terminal conformation during beta-sheet fibril formation. These immunochemical results are consistent with previous structural data, and help to explain the differential effects of A beta 1-39/40 and 1-42 on fibril formation in brain.
Kametani
F
F
Department of Molecular Biology, Tokyo Institute of Psychiatry, Japan.
Tanaka
K
K
Tokuda
T
T
Allsop
D
D
D015153:Blotting, Western; D007124:Immunoenzyme Techniques; D010446:Peptide Fragments / Q000032:analysis*; D011487:Protein Conformation
D010446:Peptide Fragments