Turning a kinase deoxyribozyme into a sensor

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Deoxyribozyme sensors typically use RNA-cleaving deoxyribozymes, susceptible to background signals from non-specific RNA cleavage.
• Analyte detection often relies on allosteric regulation, which can be prone to interference.

Purpose of the Study:

• To develop a novel deoxyribozyme-based sensor system with enhanced sensitivity and reduced background noise.
• To utilize analyte self-phosphorylation coupled with signal amplification for analyte detection.

Main Methods:

• Developed a deoxyribozyme catalyzed self-phosphorylation reaction where the analyte serves as the substrate.
• Employed rolling circle amplification (RCA) for massive signal amplification of the modified deoxyribozyme product.
• Demonstrated detection of guanosine triphosphate (GTP) using the deoxyribozyme Dk2 and a two-deoxyribozyme system.

Main Results:

• The novel system detected as low as 25 nM GTP in the presence of 1 mM ATP, demonstrating high specificity.
• A two-deoxyribozyme system, incorporating RCA and a fluorescence-generating deoxyribozyme, reported GTP from 4 μM to 1 mM.
• Successfully converted small molecule modifying deoxyribozymes into analyte sensors.

Conclusions:

• The self-phosphorylation deoxyribozyme system offers a sensitive and specific method for analyte detection.
• Coupling deoxyribozyme activity to signal amplification strategies like RCA overcomes limitations of traditional deoxyribozyme sensors.
• This approach provides a versatile platform for developing novel biosensors for various analytes.