Investigation on intermolecular interaction of synthesized azo dyes with bovine serum albumin

This research was performed using spectroscopic techniques and molecular docking to elucidate the mechanisms of interaction between bovine serum albumin (BSA) and two novel synthesized azo dyes. The titration of dyes into BSA solution results in quenching of fluorescence emission by complex formation. The UV-Vis spectroscopy confirms that formation of complex in ground state between both dyes and BSA induces conformational and micro environmental changes of the protein. Based on the calculation of the thermodynamic parameters, it can be concluded that both dyes spontaneously bind onto BSA, and van der Waals force and hydrogen bonding interaction played a predominant roles in the process of spontaneous bonding. The average binding distance (r) between protein and both dyes was calculated by Forster energy transfer measurements and revealed both dyes bind to the BSA residues of tryptophan over short distances. The results of molecular docking studies indicated that the probable binding location of both dyes is subdomain IB of BSA via hydrophobic interaction and hydrogen bond. Furthermore, as shown by synchronous fluorescence and Fourier transform infrared spectroscopy, both dyes can lead to conformational changes of BSA, which alter its biological functions. Communicated by Ramaswamy H. Sarma

Automated summary

This study used spectroscopic techniques and molecular docking to investigate the interaction mechanisms between bovine serum albumin (BSA) and two newly synthesized azo dyes. The results showed that the dyes formed complexes with BSA, leading to quenching of fluorescence emission. UV-Vis spectroscopy confirmed conformational and micro environmental changes of BSA upon complex formation. Thermodynamic calculations indicated spontaneous binding of the dyes to BSA, with van der Waals force and hydrogen bonding playing a major role in the process. Molecular docking studies revealed the probable binding site of the dyes on subdomain IB of BSA through hydrophobic interaction and hydrogen bond. Additionally, the dyes induced conformational changes in BSA, altering its biological functions.