A surface plasmon resonance-based biosensor with full-length BACE1 in a reconstituted membrane

Area of Science:

• Biochemistry
• Neuroscience
• Biotechnology

Background:

• Alzheimer's disease is a neurodegenerative disorder linked to the enzyme BACE1 (β-site amyloid precursor protein cleaving enzyme 1).
• Studying membrane-embedded BACE1 in its natural environment is crucial for understanding its role and developing effective drugs.
• Existing assays often use truncated or non-membrane-bound forms of BACE1, limiting physiological relevance.

Purpose of the Study:

• To develop a novel surface plasmon resonance (SPR) biosensor assay for analyzing membrane-embedded, full-length BACE1.
• To investigate the interactions of BACE1 with inhibitors under more physiologically relevant conditions.
• To establish a platform for studying other membrane-bound drug targets.

Main Methods:

• Development of an SPR biosensor assay utilizing an antibody for capturing His6-tagged, full-length BACE1.
• Reconstitution of a brain lipid extract membrane onto the SPR chip to embed the enzyme.
• Analysis of enzyme-inhibitor interactions and comparison with a reference surface.

Main Results:

• The developed SPR assay successfully detected interactions with BACE1 in its native lipid membrane environment.
• The functional surface demonstrated slightly different interaction characteristics compared to a reference surface with immobilized ectodomain BACE1.
• The assay confirmed the same inhibitor characteristic pH effect, validating the system's performance.

Conclusions:

• The SPR biosensor assay provides a valuable tool for studying membrane-bound BACE1 under near-physiological conditions.
• This approach enhances our understanding of BACE1's role in Alzheimer's disease and aids in the discovery of novel inhibitors.
• The methodology is adaptable for investigating other membrane-associated drug targets.