A smart adaptable metal sequestering peptide conjugate to modulate Aβ fibrillar aggregation

Area of Science:

• Biochemistry and Molecular Biology
• Neuroscience
• Materials Science

Background:

• Alzheimer's disease pathogenesis involves amyloid beta (Aβ) peptide aggregation.
• Transition metal ions (Fe3+, Cu2+, Zn2+) significantly enhance Aβ aggregation and cellular toxicity.
• Existing inhibition strategies often target only one specific metal ion.

Purpose of the Study:

• To develop a novel adaptable metal sequestering peptide (AMSP) capable of modulating metal-induced Aβ aggregation.
• To investigate the mechanism of AMSP in sequestering various transition metal ions (Zn2+, Cu2+, Fe3+) from Aβ complexes.
• To evaluate the efficacy of AMSP in inhibiting Aβ fibrillation in vitro.

Main Methods:

• Design and synthesis of a taurine-containing adaptable metal sequestering peptide (AMSP) with a VFFA recognition motif and glutamic acid pendant chain.
• Investigation of Aβ aggregation modulation in the presence of metal ions using various biophysical methods.
• Monitoring of fibril accumulation to assess the inhibitory effect of AMSP.

Main Results:

• AMSP effectively sequesters Zn2+ preferentially, along with Fe3+ and Cu2+ ions, from metal-Aβ complexes under physiological conditions.
• The peptide's structure, with taurine's -SO3H groups, facilitates metal ion chelation via interactions with Aβ histidines (His6, His13, His14).
• AMSP demonstrated efficient inhibition of Aβ aggregation induced by these metal ions.

Conclusions:

• The developed adaptable metal sequestering peptide (AMSP) is a novel and effective inhibitor of metal-induced Aβ aggregation.
• AMSP exhibits selective recognition and metal scavenging capabilities, offering a versatile approach to combat Aβ fibrillation.
• This strategy holds promise for developing new therapeutic interventions for Alzheimer's disease by targeting metal ion dysregulation.