Novel polymer linkers for single molecule AFM force spectroscopy.

Area of Science:

• Biophysics
• Materials Science
• Surface Chemistry

Background:

• Flexible polymer linkers are crucial for surface immobilization in techniques like atomic force microscopy (AFM).
• In AFM force spectroscopy, linkers facilitate covalent attachment of molecules to AFM tips and surfaces, ensuring proper orientation and separating specific interactions from background noise.
• They also serve as a reference for quantitative analysis of single-molecule events.

Purpose of the Study:

• To synthesize and test a novel polymer linker for AFM force spectroscopy.
• To explore potential applications of this linker in probing various molecular interactions.
• To demonstrate the adaptability of linker properties for diverse experimental needs.

Main Methods:

• Synthesis of polymer linkers using phosphoramidate (PA) chemistry, allowing control over length and functional groups.
• Testing of PA linkers with different functional groups in experimental systems employing various immobilization chemistries.
• Application of AFM force spectroscopy to probe interactions between DNA oligonucleotides, DNA-protein complexes (SfiI), and amyloid peptides (Aβ42).

Main Results:

• Successful synthesis of homogeneous polymer linkers with predetermined lengths and functional groups.
• Validation of the linker's feasibility in AFM force spectroscopy experiments.
• Demonstration of successful probing of DNA-DNA, DNA-protein, and peptide interactions using the synthesized linkers.

Conclusions:

• The developed phosphoramidate chemistry provides a versatile platform for creating custom polymer linkers for AFM force spectroscopy.
• The linker's properties (length, functional groups) can be tailored for specific applications, enhancing its utility.
• This approach offers broad applicability for studying molecular interactions in various biological systems using AFM.