Exclusive behaviour of asymmetric zwitterionic gemini surfactants towards lysozyme

Being essential to industrial, cosmetic and biomedical domains, protein-surfactant mixtures are enduring to be an expanse of vigorous research. Consequently, in this research article, we have explored the behaviour of two asymmetric zwitterionic geminis with lysozyme. The results of multi-spectroscopic methods (fluorescence, UV-visible, CD) have revealed that the n(-)-2-(+)m geminis form complex with Hen-Egg-White Lysozyme (HEWL). The binding parameters suggest that 10(-)-2-(+)16 complexes significantly to HEWL than 8(-)-2-(+)16. Pyrene and synchronous fluorescence disclosed microenvironmental fluctuations in the lysozyme solution upon zwitterionic gemini combination. CD spectra have demonstrated mitigation of negative helicity, thereby confirming conformational changes in HEWL on surfactant addition. Molecular docking hints at the binding of n(-)-2-(+)m in the locality of Trp-108, Trp-62 and Trp-63. Intriguingly, exceptional hydrogen bonding interaction was observed between Trp-63 of HEWL and phosphate group of 8(-)-2-(+)16. However, no such bonding was observed in 10(-)-2-(+)16. Moreover, lower root-mean-square deviations (RMSD) and radius- of- gyration (Rg) values obtained in molecular simulation indicated the formation of stable protein-surfactant complexes. This study would be significant in understanding the in-depth molecular interactions of zwitterion-protein mixtures. (C) 2021 Elsevier B.V. All rights reserved.