Quaternized styryl-azinium fluorophores as cellular RNA-binders

Area of Science:

• Biophysical Chemistry
• Molecular Biology
• Cell Biology

Background:

• Quaternized styryl-azinium iodides are investigated for their potential in nucleic acid binding.
• Understanding the interaction between small molecules and RNA is crucial for developing novel therapeutic and diagnostic tools.

Purpose of the Study:

• To evaluate the RNA-binding capability of three quaternized styryl-azinium iodides.
• To characterize the binding interactions and excited-state dynamics of these compounds with RNA.

Main Methods:

• Fluorescence Confocal Microscopy imaging of MCF-7 cells treated with RNase.
• Spectrophotometric and fluorimetric titrations with transfer RNA (tRNA) and deoxyribonucleic acid (DNA).
• Femtosecond-resolution transient absorption spectroscopy.

Main Results:

• The quaternized styryl-azinium iodides demonstrated significant binding affinity for cellular RNA.
• Association constants indicated preferential binding to tRNA over DNA.
• Transient absorption spectroscopy revealed a lengthening of the S₁ state lifetime upon complexation with tRNA.
• Complexation led to an enhancement in fluorescence quantum yield.

Conclusions:

• The studied compounds exhibit promising RNA-binding properties.
• The observed changes in excited-state dynamics provide insights into the molecular mechanisms of RNA-compound interaction.
• These findings support the potential application of these styryl-azinium iodides in biological contexts involving RNA.