Multispectroscopic and Computational Analysis Insight into the Interaction of Cationic Diester-Bonded Gemini Surfactants with Serine Protease α-Chymotrypsin

Accumulation of different protein-surfactant mixtures affords further knowledge about the structure-property interactions of biomacromolecules. They will help design suitable surfactants, which, in turn, can enhance the utilization of protein-surfactant complexes in biotechnologies, cosmetics, and food industry realms. Owing to their adaptable and remarkably notable properties, we are describing herein the interaction of C m -E2O-C m gemini surfactants ( m = 12, 14, and 16) with α-CHT by employing various spectroscopic techniques including with molecular docking and density functional theory (DFT) method. Results have revealed complex formation, unfolding, and a static quenching mechanism in the interaction of gemini surfactants with α-CHT. The Stern-Volmer constant ( K SV ), quenching constant ( k q ), the number of binding sites ( n ), and binding constant ( K b ) were interrogated by utilizing the fluorescence quenching method, UV-vis, synchronous, 3-D, and resonance Rayleigh scattering fluorescence studies. The data perceive the α-CHT-C m -E2O-C m complex formation along with conformational alterations induced in α-CHT. The contribution of aromatic residues to a nonpolar environment is illustrated by pyrene fluorescence. Fourier transform infrared spectroscopy and circular dichroism outcomes reveal conformational modifications in the secondary structure of α-CHT with the permutation of gemini surfactants. The computational calculations (molecular docking and DFT) further corroborate the complex formation between α-CHT and C m -E2O-C m gemini surfactants and the contribution of electrostatic/hydrophobic interaction forces therein.