Bait and Cleave: Exosite-Binding Peptides on Quantum Dots Selectively Accelerate Protease Activity for Sensing with...

Area of Science:

• Biotechnology
• Nanotechnology
• Biochemistry

Background:

• Quantum dots (QDs) possess advantageous optical properties for bioanalysis and imaging.
• Previous QD surface chemistry modulated protease activity non-specifically.
• Selective protease detection remains a challenge in bioanalytical applications.

Purpose of the Study:

• To develop a strategy for selectively accelerating target protease activity using QD-peptide conjugates.
• To enhance the sensitivity and specificity of protease detection.
• To enable detection of target proteases in complex biological backgrounds.

Main Methods:

• Conjugating "bait" peptides, derived from various protein types, to quantum dots (QDs).
• Utilizing exosite-binding peptides to increase QD-peptide conjugate affinity for specific proteases (thrombin, factor Xa).
• Evaluating the effect of these conjugates on the proteolysis rates of coconjugated substrates.

Main Results:

• Achieved protease activity acceleration of up to two orders of magnitude.
• Demonstrated high specificity for target proteases, with negligible acceleration of others.
• Improved detection limits by over an order of magnitude.
• Enabled target protease detection against a background of non-target proteolysis and mitigated inhibitor effects.

Conclusions:

• The "bait and cleave" strategy offers a generalizable approach for rational design of nanoparticle-based enzyme sensors.
• This method significantly enhances sensitivity and selectivity in protease detection.
• The findings represent a major advancement in developing advanced bioanalytical tools.