The multi-spectroscopic approach on the interaction between rabbit serum albumin and cationic surfactant: Investigation on the formation and solubilization of the protein aggregation

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2020-10, Vol.239, p.118542, Article 118542
• Main Authors: Srivastava, Rachana, Alam, Md. Sayem
• Format: Article
• Language: English
• Subjects: CMC; CTAB; Protein-denaturation; Protein-folding; Rabbit serum albumin
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2020.118542

The protein-surfactant interaction studies have great importance in the range of the application like cosmetics, food, pharmaceutical, detergent industries, and many more. In this study, we have studies protein (rabbit serum albumin, RSA) and a cationic surfactant (cetyltrimethylammonium bromide, CTAB) interaction at different physiological conditions (viz., pH, ionic strength, surfactants concentrations, protein concentration, and many more). They form the protein surfactant complexes. The interchange of electrostatic and hydrophobic force monitors the change in complexes. The three different pHs (below (4.0), above (7.0) and at (4.7) the isoelectric point of RSA) of the medium indicate the three different charges on the protein while surfactant is positive in charge. Critical micelle concentration (CMC) plays a significant role in protein-surfactant interaction. CTAB unfolds the protein at its specific concentration range afterward again; it starts refolded. RSA interacted, with the addition of the CTAB is characterized by many spectroscopic methods like UV–visible, fluorescence, fluorescence time-resolved, circular dichroism, and topographical changes monitored by the AFM. In fluorescence spectra, the blue shift shows the unfolding of RSA. The molecular docking indicates the binding energy of 5.8 kcal mol−1. The changes below and above the CMC is significant. RSA interacted with micelle of CTAB and form RSA-CTAB complex. [Display omitted] •The study shows the RSA and CTAB interaction at three different pHs.•The aggregation rate will change above and below the CMC.•Lifetime indicates the aggregation frequency is higher above the CMC.•AFM images show the change in size of protein aggregates below and above the CMC.•CMC plays an important role in protein's aggregation.