Kabir Shahanaz, Hossain Md Al Amin, Jahan Israt, Ahmed Bulbul, Malik Ajamaluddin, Goni Md Abdul, Hoque Md Anamul, Anis-Ul-Haque K M
Department of Chemistry, Jashore University of Science and Technology, Jashore 7408, Bangladesh.
Department of Chemistry, Jashore University of Science and Technology, Jashore 7408, Bangladesh.
Int J Biol Macromol. 2025 Feb;291:138990. doi: 10.1016/j.ijbiomac.2024.138990. Epub 2024 Dec 21.
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), enthalpy (∆H), and entropy (∆S)-were analyzed to identify the driving forces behind micellization. The negative ∆G indicated spontaneous aggregation, with ∆H and ∆S 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.
本研究利用电导分析和分子对接技术探索胃蛋白酶与十二烷基硫酸钠（SDS）之间的相互作用，以加深我们对胃蛋白酶作用的理解。进行了电导研究，以考察在300.55 K至320.55 K温度范围内，以5 K为增量，在各种钠电解质（溴化钠、硫酸钠、磷酸钠和醋酸钠）的水溶液中，SDS与胃蛋白酶的胶束化行为。SDS - 胃蛋白酶体系的临界胶束浓度（CMC）受胃蛋白酶浓度、电解质类型和温度的影响。发现胃蛋白酶抑制SDS胶束化，使CMC增加，而电解质促进胶束化，使CMC降低。分析了热力学参数——吉布斯自由能（∆G）、焓（∆H）和熵（∆S）——以确定胶束化背后的驱动力。负的∆G表明自发聚集，∆H和∆S表明疏水和静电相互作用。分子对接进一步证实了这些相互作用，揭示了SDS的疏水尾部与胃蛋白酶在结构域间裂隙处的非极性结合口袋之间的结合。这些发现为表面活性剂 - 酶相互作用提供了见解，在生物化学、药理学和食品科学中有潜在应用。
