An insight into the binding of an ester functionalized gemini surfactant to hemoglobin

Abstract Fluorescence, UV–vis, Circular dichroism (CD) spectroscopy and surface tension techniques were employed to investigate the interaction between the hemoglobin (Hb) and gemini surfactant, bis (N, N-dimethyl-N-hexadecylammoniumacetoxy) dichloride (16-E2-16). Molecular docking and simulation have also been done to study the changes in the Hb conformation upon interacting with 16-E2-16. The UV–vis study demonstrates the perturbation of the soret/heme band and generates conformational heterogeneity within the heme group in the presence of 16-E2-16. Data shows an increase in the fluorescence intensity of Hb with the addition of 16-E2-16. After the cmc value of the 16-E2-16 the fluorescence intensity increases slowly. Trp fluorescence was largely affected than that of Tyr. The critical micellar concentration of 16-E2-16 in absence and presence of Hb at various temperatures were determined using surface tension plots. The cmc increases with an increase in temperature as well as in the presence of Hb. Furthermore, thermodynamic parameters of micellization were also investigated. Docking study reveals that 16-E2-16 binds in the α1 and β2 chain of Hb with predominant forces being hydrophobic and electrostatic. Simulation and CD study confirms the conformational change in the Hb after binding with 16-E2-16.