Novel high-affinity Aβ-binding peptides identified by an advanced in vitro evolution, progressive library method.

Area of Science:

• Biochemistry
• Molecular Biology
• Neuroscience

Background:

• Amyloid-beta 42 (Aβ42) oligomers are implicated in Alzheimer's disease pathogenesis.
• Peptides binding to Aβ42 are of significant interest for Alzheimer's disease diagnosis and therapy.

Purpose of the Study:

• To apply a systemic in vitro evolution method, the progressive library method (PLM), to identify high-affinity Aβ42-binding peptide aptamers.
• To validate the effectiveness of the PLM approach for discovering novel functional peptides.

Main Methods:

• Systemic in vitro evolution using the progressive library method (PLM).
• Construction and selection from primary and secondary peptide libraries.
• Affinity measurement using surface plasmon resonance (SPR).
• Binding confirmation via a novel gel shift assay (fluorescence enhancement).

Main Results:

• Identification of high-affinity peptide aptamers (8-9 amino acids) that bind to Aβ42.
• SPR measurements indicated affinities comparable to or higher than previously reported peptides (Kd of 10⁻⁷).
• Novel binding peptides were confirmed using a fluorescence-based gel shift assay.

Conclusions:

• The progressive library method (PLM) is effective for identifying high-affinity Aβ42-binding peptides.
• The identified peptides offer potential for Alzheimer's disease diagnosis and therapeutic strategies.
• This study demonstrates the utility of systemic in vitro evolution for discovering functional peptides.