RNA-Binding Efficacy of N-Phenylbenzohydroxamic Acid: An Invitro and Insilico Approach

Abstract

RNA has attracted recent attention for its key role in gene expression and hence targeting by small molecules for therapeutic intervention. This study is aimed to elucidate the specificity of RNA binding affinity of parent compound of N-arylhydroxamic acids series, N-phenylbenzohydroxamic acid trivially named as PBHA,C6H5NOH.C6H5C ˭ O. The binding behavior was examined by various biophysical methods such as absorption, fluorescence, and viscosity measurements. Molecular docking was also done. The value of affinity constant and overall binding constant was calculated 5.79 ± 0.03 × 10⁴ M⁻¹ and K’ = 1.09 ± 0.03 × 10⁵ M⁻¹, respectively. The Stern-Volmer constant K_sv obtained was 2.28 ± 0.04 × 10⁴ M⁻¹. The compound (PBHA) shows a concentration-based enhancement of fluorescence intensity with increasing RNA concentration. Fluorescence quenching of PBHA–RNA complex in presence of K₄ [Fe(CN)₆] was also observed. Viscometric studies complimented the UV results where a continuous increase in relative viscosity of the RNA solution was observed with added optimal PBHA concentration. All the experimental evidences indicate that PBHA can strongly bind to RNA through an intercalative mode.

Keywords:

• Hydroxamic acid
• PBHA
• RNA
• binding
• fluorescence
• viscosity
• intercalation