Exploration of the micellization behavior of sodium dodecyl sulfate in aqueous solution of gastric enzyme pepsin: Assessment of the consequences of sodium electrolytes and temperature

Shahanaz Kabir; Md Al Amin Hossain; Israt Jahan; Bulbul Ahmed; Ajamaluddin Malik; Md Abdul Goni; Md Anamul Hoque; K M Anis-Ul-Haque

doi:10.1016/j.ijbiomac.2024.138990

Exploration of the micellization behavior of sodium dodecyl sulfate in aqueous solution of gastric enzyme pepsin: Assessment of the consequences of sodium electrolytes and temperature

Int J Biol Macromol. 2024 Dec 21:291:138990. doi: 10.1016/j.ijbiomac.2024.138990. Online ahead of print.

Authors

Shahanaz Kabir¹, Md Al Amin Hossain¹, Israt Jahan², Bulbul Ahmed³, Ajamaluddin Malik⁴, Md Abdul Goni⁵, Md Anamul Hoque³, K M Anis-Ul-Haque⁶

Affiliations

¹ Department of Chemistry, Jashore University of Science and Technology, Jashore 7408, Bangladesh.
² Department of Chemistry, Jashore University of Science and Technology, Jashore 7408, Bangladesh. Electronic address: i.jahan@just.edu.bd.
³ Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh.
⁴ Department of Biochemistry, Collage of Science, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia.
⁵ Department of Biological and Physical Sciences, South Carolina State University, Orangeburg, SC 29117, USA.
⁶ Department of Chemistry, Jashore University of Science and Technology, Jashore 7408, Bangladesh. Electronic address: a.haque@just.edu.bd.

PMID: 39716714
DOI: 10.1016/j.ijbiomac.2024.138990

Abstract

This study explores the interactions between pepsin and sodium dodecyl sulfate (SDS) using conductometric analysis and molecular docking to deepen our understanding of the role of pepsin. Conductometric studies were conducted to examine the micellization behavior of SDS with pepsin in aqueous solutions of various sodium electrolytes (NaBr, Na₂SO₄, Na₃PO₄, and CH₃COONa) at temperatures ranging from 300.55 K to 320.55 K in 5 K increments. The critical micelle concentration (CMC) of the SDS-pepsin system was influenced by pepsin concentration, electrolyte type, and temperature. Pepsin was found to inhibit SDS micellization, increasing the CMC, while electrolytes promoted micellization, decreasing the CMC. Thermodynamic parameters-Gibbs free energy (∆G_m⁰), enthalpy (∆H_m⁰), and entropy (∆S_m⁰)-were analyzed to identify the driving forces behind micellization. The negative ∆G_m⁰ indicated spontaneous aggregation, with ∆H_m⁰ and ∆S_m⁰ suggesting hydrophobic and electrostatic interactions. Molecular docking further confirmed these interactions, revealing binding between the hydrophobic tail of SDS and nonpolar binding pocket of pepsin at the interdomain cleft. These findings provide insights into surfactant-enzyme interactions, with potential applications in biochemistry, pharmacology, and food science.

Keywords: Molecular docking; Pepsin protein; Protein-surfactant interaction.