Functional-group specific aptamers indirectly recognizing compounds with alkyl amino group

Area of Science:

• Biochemistry
• Molecular Biology
• Organic Chemistry

Background:

• Aptamers typically target specific molecules, limiting their use for broad applications.
• Recognizing common molecular features is crucial for developing versatile aptamers.
• Amino groups require modification for effective aptamer selection.

Purpose of the Study:

• To select aptamers capable of indirectly recognizing alkyl amino groups.
• To demonstrate a chemical conversion strategy for aptamer development against challenging targets.
• To explore new applications for aptamers targeting common molecular moieties.

Main Methods:

• Chemical modification of amino groups using p-nitrobenzene sulfonyl (p-nosyl).
• Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique for aptamer generation.
• Characterization of aptamer affinity, specificity, and structural properties (G-quadruplex).

Main Results:

• Selected aptamers (M6b-M14, M13a) show high affinity (K(d) 2-5 μM) for p-nosyl-protected amino groups.
• Aptamers exhibit specificity for compounds with p-nosyl-protected amino groups, excluding those with α-carboxyl groups.
• An aptamer beacon successfully recognized lysine in amino acid mixtures, demonstrating indirect detection capability.

Conclusions:

• Aptamers can be selected to recognize common structural features (p-nosyl-protected amino groups) of molecules.
• Chemical modification provides a viable strategy for aptamer selection against difficult-to-target compounds.
• This approach broadens the utility of aptamers in diagnostics and molecular recognition.