Enantiomeric interactions between nucleic acid bases and amino acids on solid surfaces

Area of Science:

• Surface science
• Molecular interactions
• Chirality studies

Background:

• Molecular interactions between nucleic acids and amino acids are crucial in biology.
• Adsorbing molecules on surfaces enables detailed study using high-resolution imaging techniques like scanning tunnelling microscopy (STM).
• Chemisorption of prochiral molecules, such as adenine, on metal surfaces induces chirality.

Purpose of the Study:

• To investigate the chiral preference in the interaction between adenine chains and alpha-amino acids.
• To demonstrate diastereoisomeric interactions at the molecular level.
• To highlight the capability of STM in studying such detailed molecular interactions.

Main Methods:

• Adsorption of adenine on a Cu[110] surface to form homochiral chains.
• Utilizing scanning tunnelling microscopy (STM) for high-resolution imaging.
• Observing the interaction of phenylglycine enantiomers with adenine chains.

Main Results:

• Adenine adsorption on Cu[110] results in homochiral chains with directionality correlated to chirality.
• Phenylglycine exhibited a strong chiral preference, with S-phenylglycine and R-phenylglycine binding exclusively to specific chain orientations.
• STM images confirmed diastereoisomeric interactions involving phenylglycine and adenine chains.

Conclusions:

• The direction of adenine chains on Cu[110] is intrinsically linked to their induced chirality.
• Phenylglycine enantiomers demonstrate highly specific binding to these chiral adenine chains.
• This study provides the first molecular-level observation of diastereoisomeric interactions, showcasing STM's power in this field.