Kinase Sensing Based on Protein Interactions at the Catalytic Site

Area of Science:

• Biochemistry
• Biotechnology
• Biosensor Technology

Background:

• Kinases regulate cellular processes and are key biomarkers for diseases like cancer.
• Existing biosensors detect kinases via ATP-dependent phosphorylation, often requiring chemical labeling.
• There is a need for novel kinase detection methods with enhanced selectivity and reduced complexity.

Purpose of the Study:

• To introduce a new interaction-based electrochemical kinase biosensor.
• To demonstrate a label-free detection method for kinases based on protein-protein interactions.
• To enable selective detection of enzymes without relying on enzymatic activity.

Main Methods:

• Developed an electrochemical biosensor using a peptide monolayer of a kinase substrate (HDGF) on a gold electrode.
• Utilized the interaction between the kinase (ERK2) catalytic site and the substrate phosphorylation site for sensing.
• Measured changes in redox-active species permeability through the monolayer upon kinase binding.
• Performed surface chemistry analysis to confirm kinase-substrate interaction.

Main Results:

• Successfully detected ERK2 kinase using the interaction-based biosensor without ATP.
• Achieved a sensitivity down to 10 nM ERK2, within the range of cellular concentrations.
• Confirmed ERK2 binding to the HDGF peptide monolayer via surface chemistry.
• Demonstrated that kinase binding alters monolayer permeability, enabling electrochemical detection.

Conclusions:

• The developed biosensor offers a novel approach for kinase detection based on direct protein-protein interactions.
• This method eliminates the need for chemical labeling and ATP, simplifying the detection process.
• The interaction-based sensing strategy holds potential for the selective detection of various enzymes beyond kinases.