Entropy driven binding of the alkaloid chelerythrine to polyadenylic acid leads to spontaneous self-assembled structure formation

Structural and thermodynamic basis of interaction of the putative anticancer agent chelerythrine with single, double and triple-stranded RNAs

“…56 The excitation wavelength of CHL was at xed at 338 nm and the emission spectra was monitored in the range of 450-650 nm. 57 All the measurements were performed keeping an excitation and emission band pass of 5 nm at 20 AE 1.0 C. The amount of free and bound alkaloid was determined as follows. In absorption spectroscopy, aer each addition of the alkaloid to the RNA solution from the absorbance value at the isosbestic points (A iso ) the total alkaloid concentration present was calculated as C t ¼ A iso /l3 iso .…”

Deciphering binding affinity, energetics, and base specificity of plant alkaloid Harmane with AT and GC hairpin duplex DNA

“…They are recognized as sensitive probes for observing DNA structure, providing affinity for site-specificity in molecular biology and yielding important properties for drug design and therapeutic potential in controlling the gene expression. [34][35][36][37][38][39][40][41][42][43] The interaction of biological entities such as ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein with the ligand is a prominent area of exploration in developing biomedical significance. [39,[44][45][46][47][48][49][50] DNA acts as an important part of storing the genetic information that is the potential therapeutic target in cancer and various other diseases.…”

Coralyne induced self-structure in polyadenylic acid: Thermodynamics of the structural reorganization

“…The K value decreased on increasing the [K + ] from 50 to 130 mM. Earlier studies on the induction of self-structure by small molecules like methylene blue, chelerythrine, proflavine, azure A and azure B have shown that the K value increases with increase in salt concentration [30,32,34,35]. However, in the case of coralyne here the K values decreased from {(3.12 ± 0.12)Á10 6 to (2.46 ± 0.11)Á10 6 to (1.91 ± 0.09)}Á10 6 M À1 on increasing the [K + ] from {(50 ± 0.01) to (75 ± 0.01) to (100 ± 0.01)} mM.…”

“…Therefore, the non-polyelectrolytic forces which included van der Waals interactions, H-bonding, p-p stacking, and hydrophobic transfer dominated the coralyne induced self-structure formation in poly(A). Previous studies have also indicated that the induction of self-structure in poly(A) is mainly favoured by non-polyelectrolytic forces [29,34,35].…”

“…Poly(A) has single stranded helical structure at neutral pH but some small molecules and alkaloids can induce unique self-structure (double stranded) in poly(A) at neutral pH where otherwise only single stranded structure can exist [13,15,[26][27][28][29][30][31][32][33][34][35]. Such self-structure induction can influence mRNA degradation and stop protein production in the cell.…”