Surface-immobilized peptide aptamers as probe molecules for protein detection

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• Peptide aptamers offer specific molecular recognition capabilities.
• Engineering protein scaffolds enhances peptide aptamer stability and binding affinity.
• Controlled surface immobilization is crucial for aptamer-based detection systems.

Purpose of the Study:

• To demonstrate surface-immobilized, oriented peptide aptamers for specific protein detection.
• To investigate the impact of orientation on peptide aptamer binding affinity and function.
• To assess the selectivity of engineered peptide aptamers in complex biological samples.

Main Methods:

• Engineering peptide aptamers within a stefin A scaffold with a unique cysteine residue for oriented immobilization.
• Utilizing dual-polarization interferometry to measure binding affinity and orientation effects.
• Testing aptamer selectivity using complex biological solutions with low target protein concentrations.

Main Results:

• Demonstrated a strong relationship between aptamer orientation and binding affinity.
• Determined the affinity constant (KD) for an oriented peptide aptamer ST(cys+)_(pep9) binding to CDK2.
• Confirmed the high selectivity of the peptide aptamer STM_(pep9) in complex biological solutions.

Conclusions:

• Surface-immobilized, oriented peptide aptamers are effective tools for specific protein detection.
• Protein scaffold engineering and controlled orientation enhance aptamer performance.
• This approach shows promise for sensitive and selective biomarker detection in biological samples.