Direct Observation of Amyloid β Behavior at Phospholipid Membrane Constructed on Gold Nanoparticles

Abstract

Amyloid β (Aβ) is a potential biomarker of Alzheimer's disease (AD), and its fibrillation behavior is of interest and value. In this study, the Aβ behaviors on phospholipid membranes were observed by Membrane Surface-Enhanced Raman Spectroscopy (MSERS) method. Phospholipid (PL) membranes, consisting of DMPC and DMPS with a molar ratio of 9:1, were fabricated on gold nanoparticles with diameter of 100 nm (Au@PL). Enhancement of the Raman intensity of Au@PL was increased by Aβ, with enhancement factor about 40. The H-bonding network was disturbed in presence of NaCl which covered Au@PL and made Au@PL away from one another. When Aβ was applied with Au@PL, the H-bonding network was disturbed just after mixing. As the reaction reaches to equilibrium, Aβ attracted neighbouring Au@PL and induced aggregation of Au@PL which blocked the aggregation prone site of Aβ to inhibit further fibrillation. Based on our method, the Aβ behaviors at lipid membrane surface can be directly observed via enhanced Raman signals.

Recent advances in nanotherapeutics for epilepsy and neurodegenerative diseases

“…These findings hold promise for the diagnosis and management of AD by utilizing nanotechnology-based approaches. 23,24…”

Surface enhanced Raman scattering for probing cellular biochemistry

“…103 The potential of SERS spectra to reveal changes in protein secondary structure based on specific components of the amide I band and also the amide III region is illustrated in in vitro studies of BSA and myoglobin 104 and of amyloid β fibrils under different conditions, respectively. 105,106 Although these particular proteins may not be representative as common intracellular components, the sensitivity of gold-nanostructure based SERS spectra with respect to changes in the intramolecular interaction illustrates the potential of intrinsic protein SERS to characterize protein structure in living cells.…”

Potential Role of Nanoparticles in Treating the Accumulation of Amyloid-Beta Peptide in Alzheimer’s Patients

“…Aβ attracted the adjacent Au@PL as the reaction reached equilibrium and induced an Au@PL aggregation that blocked Aβ’s vulnerable aggregation to prevent further fibrillation. Based on our system, the behavior of the Aβ on the lipid membrane surface can be observed directly through enhanced Raman signals [ 78 ].…”