Ã?²-Carbolines (Ã?²Cs) belong to the naturally occurring alkaloid family, derived from 9H-pyrido[3,4-b]indole, also known as\nnorharmane (Hnor). Knowing the importance of the Ã?²Cs alkaloid family in biological processes, a comprehensive binding study is\nreported of four Ag(I) compounds containing the ligand Hnor and having different counteranions, namely, NO3\nâË?â??, ClO4\nâË?â??, BF4\nâË?â??,\nand PF6\nâË?â??, with human serum albumin (HSA) as a model protein. Different approaches like UV-visible, fluorescence spectroscopy,\ncircular dichroism (CD), and molecular docking studies have been used for this purpose.Thefluorescence results establish that the\nphenomenon of binding of Ag(Hnor) complexes to HSA can be deduced from the static quenching mechanism. The results\nshowed a significant binding propensity of the used Ag(I) compounds towards HSA. The role of the counteranion on the binding\nof Ag(I) compounds to HSA appeared to be remarkable. Compounds with (ClO4\nâË?â??) and (NO3\nâË?â??) were found to have the most\nefficient binding towards HSA as compared to BF4\nâË?â??and PF6\nâË?â??. Circular dichroism (CD) studies made clear that conformational\nchanges in the secondary structure of HSA were induced by the presence of Ag(I) compounds. Also, the Ã?±-helical structure of HSA\nwas found to get transformed into a Ã?²-sheeted structure. Interestingly, (ClO4\nâË?â??) and (NO3\nâË?â??) compounds were found to induce\nmost substantial changes in the secondary structure of HSA. The outcome of this study may contribute to understanding the\npropensity of proteins involved in neurological diseases (such as Alzheimerââ?¬â?¢s and Parkinsonââ?¬â?¢s diseases) to undergo a similar\ntransition in the presence of Ag-Ã?²-carboline compounds.
Loading....