Synthesis and biophysical analysis of modified thymine-containing DNA oligonucleotides

Area of Science:

• Biochemistry
• Molecular Biology
• Organic Chemistry

Background:

• Thymidine is a fundamental component of DNA.
• Eukaryotic DNA contains various naturally occurring thymidine modifications.
• Understanding the structural impact of these modifications is crucial for DNA function and stability.

Purpose of the Study:

• To synthesize a 5-formyl-2 -deoxyuridine (5fU) phosphoramidite building block.
• To prepare synthetic oligonucleotides containing all known eukaryotic thymidine modifications.
• To investigate the biophysical and structural consequences of these modifications in DNA.

Main Methods:

• Chemical synthesis of 5-formyl-2 -deoxyuridine phosphoramidite.
• Oligonucleotide synthesis incorporating natural thymidine derivatives.
• Biophysical characterization techniques (e.g., spectroscopy, melting temperature analysis).

Main Results:

• Successful synthesis of the 5fU phosphoramidite.
• Preparation of oligonucleotides containing diverse eukaryotic thymidine modifications.
• Biophysical data indicated that 5fU significantly alters DNA structure, while other T-derivatives did not show comparable effects.

Conclusions:

• The 5fU phosphoramidite is a valuable tool for studying DNA modifications.
• 5-formyl-2 -deoxyuridine is a structurally significant thymidine derivative in eukaryotic DNA.
• This study provides insights into how specific DNA modifications influence DNA conformation.