C-Terminal Fragment, Aβ32-37, Analogues Protect Against Aβ Aggregation-Induced Toxicity.

Area of Science:

• Biochemistry
• Neuroscience
• Drug Discovery

Background:

• Amyloid-beta (Aβ) aggregation is a central pathological hallmark of Alzheimer's disease (AD).
• Developing effective inhibitors for Aβ aggregation is crucial for AD therapeutic strategies.

Purpose of the Study:

• To design and synthesize novel peptide-based inhibitors targeting Aβ aggregation.
• To evaluate the efficacy of these peptides in preventing Aβ-induced toxicity and aggregation.

Main Methods:

• Synthesis of over 40 novel hexapeptides based on the Aβ32-37 fragment.
• In vitro evaluation using MTT-based cell viability assays to assess Aβ toxicity.
• Thioflavin T (ThT) fluorescence assays to quantify Aβ aggregation.
• Circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM) for structural and morphological analysis.

Main Results:

• Several synthesized hexapeptides demonstrated significant Aβ aggregation inhibitory activity at sub-micromolar concentrations.
• A specific hexapeptide (1) completely mitigated Aβ toxicity in cell cultures at 2 μM.
• ThT assays showed no increase in fluorescence when Aβ was incubated with hexapeptide (1), indicating inhibition of fibril formation.
• CD and TEM analyses corroborated the inhibitory effects of the peptide on Aβ aggregation.

Conclusions:

• Peptide-based inhibitors, derived from Aβ32-37, are effective in preventing Aβ aggregation and toxicity.
• Hexapeptide (1) shows potent therapeutic potential for Alzheimer's disease by inhibiting amyloid pathology.