Background:
The structural transition of aggregating Abeta peptides is the key event in
the progression of Alzheimer’s Disease (AD).
Objective:
In the present work, the structural modifications of toxic Aβ25-35 and the scrambled
Aβ35-25 were studied in Trifluoroethanol (TFE) and in aqueous SDS micelles.
Methods:
Using CD spectroscopic investigations, the conformational transition of Aβ25-35 and
Aβ35-25 peptides were determined in different membrane mimicking environments such as TFE and
SDS. An interval scan CD of the peptides on evaporation of TFE was performed. TFE titrations
were carried out to investigate the intrinsic ability of the structural conformations of peptides.
Results:
We show by spectroscopic evidence that Aβ25-35 prefers beta sheet structures upon
increasing TFE concentrations. On the other hand, the non-toxic scrambled Aβ35-25 peptide only
undergoes a transition from random coil to α-helix conformation with increasing TFE. In the
interval scan studies, Aβ25-35 did not show any structural transitions, whereas Aβ35-25 showed
transition from α-helix to β-sheet conformation. In membrane simulating aqueous SDS micelles,
Aβ25-35 showed a transition from random coil to α-helix while Aβ35-25 underwent transition from
random coil to β-sheet conformation.
Conclusion:
Overall, the current results seek new insights into the structural properties of
amyloidogenic and the truncated sequence in membrane mimicking solvents.
13C Solid-State NMR Analysis of the Chemical Structure in Petroleum Coke during Idealized In Situ Combustion Conditions
