Programmed Aptamer Screening, Characterization, and Rapid Detection for α-Conotoxin MI

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• α-conotoxin MI (CTX-MI) is a potent neurotoxin posing significant health risks due to its toxicity and lack of specific detection methods.
• The absence of specific recognition elements hinders the development of effective countermeasures and diagnostic tools for CTX-MI.
• Aptamers offer a promising alternative to traditional recognition elements, with demonstrated utility in molecular detection and drug development.

Purpose of the Study:

• To screen and characterize aptamers with high affinity and specificity for α-conotoxin MI (CTX-MI).
• To develop a sensitive and rapid aptasensor for CTX-MI detection.
• To establish a versatile aptamer screening methodology applicable to other conotoxins.

Main Methods:

• Programmed screening process to identify CTX-MI specific aptamers.
• Characterization of aptamer affinity using affinity constant (K_D) measurements.
• Development of a biolayer interferometry (BLI) based aptasensor.
• Evaluation of aptasensor performance including precision, specificity, and limit of detection (LOD).

Main Results:

• An aptamer, MBMI-01c, was isolated with a high affinity (K_D = 0.524 μM) for CTX-MI.
• MBMI-01c forms an antiparallel G-quadruplet (GQ) structure crucial for specific CTX-MI recognition.
• The developed BLI-based aptasensor demonstrated high precision, specificity, and repeatability with an LOD of 0.26 μM.
• The aptasensor achieved rapid CTX-MI detection within 10 minutes.

Conclusions:

• MBMI-01c is a highly effective aptamer for specific CTX-MI recognition.
• The developed aptasensor offers a precise, rapid, and repeatable method for CTX-MI detection.
• The aptamer holds potential for CTX-MI enrichment, detoxification, and biological studies.
• The aptamer screening methodology is adaptable for other conotoxins, expanding its utility.