Biophysical perspective of the binding of ester-functionalized gemini surfactants with catalase

Abstract

Interaction of surfactants with biomacromolecules is an essential subject of biophysical chemistry to address their diverse applications in industry, biomedical, and cosmetic domains. In this context, we have examined the binding interactions of three ester-functionalized surfactants (m-E2-m) with bovine liver catalase (BLC, 10μM) by employing a multi-technique approach. The m-E2-m geminis quench fluorescence intensity of BLC through static procedure. The binding ability of concerned gemini surfactants was found to be in the order 12-E2-12 (Kb=2.3×10(2))>16-E2-16 (Kb=1.1×10(2))>14-E2-14 (Kb=1.0×10(2)). Quenching efficacy, as determined by Ksv values, were observed as 12-E2-12 (3.0×10(2))>16-E2-16 (1.4×10(2))>14-E2-14 (1.0×10(2)). The negative ΔG°b values (12-E2-12 (-13.48kJ/mol)>16-E2-16 (-11.65kJ/mol)>14-E2-14 (-11.41kJ/mol)) indicate spontaneous nature of m-E2-m-BLC interactions. UV-vis spectroscopy, circular dichroism (CD) and micropolarity (F1/F3) assessments indicate conformational changes in BLC upon m-E2-m combination. ITC confirms the stability of BLC upon gemini combination. Docking provides support to fluorescence results by presenting the localization site of m-E2-m surfactants near to aromatic residues (mainly Tyr, Trp and Phe). Moreover, since surfactant-protein interactions have essential miscellaneous implications, therefore, this study can be significant for industrial and biomedical realms.

Keywords: Catalase; Docking; Quenching; m-E2-m.