Acidic sophorolipid biosurfactant protects serum albumin against thermal denaturation

Sophorolipids (SLs) constitute a group of unique biosurfactants in light of their unique properties, among which their physicochemical characteristics and antimicrobial activity stand out. SLs can exist mainly in acidic and lactonic forms, both of which display inhibitory activity. This study explor...

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Detalles Bibliográficos
Autores: Ortiz, Julia, Franco Marcelino, Paulo Ricardo, Teruel Puche, José Antonio, Aranda Martínez, Francisco José, Ortiz López, Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universidad de Murcia
Repositorio:DIGITUM. Depósito Digital Institucional de la Universidad de Murcia
OAI Identifier:oai:digitum.um.es:10201/187030
Acceso en línea:https://doi.org/10.3390/ijms26178752
http://hdl.handle.net/10201/187030
Access Level:acceso abierto
Palabra clave:Sophorolipid
Biosurfactant
Bovine Serum Albumin
BSA
No relacionado con ningún objetivo de desarrollo sostenible
Descripción
Sumario:Sophorolipids (SLs) constitute a group of unique biosurfactants in light of their unique properties, among which their physicochemical characteristics and antimicrobial activity stand out. SLs can exist mainly in acidic and lactonic forms, both of which display inhibitory activity. This study explores the interaction of non-acetylated acidic SL with bovine serum albumin (BSA). SL significantly enhances BSA’s thermal stability, increasing its midpoint unfolding temperature from 61.9 °C to approximately 76.0 °C and ΔH from 727 to 1054 kJ mol−1 at high concentrations, indicating cooperative binding. Fourier-Transform Infrared Spectroscopy (FTIR) analysis confirms SL’s protective effect against thermal unfolding, enabling BSA to maintain its helical structure at 70 °C, distinguishing it from other surfactants that cause denaturation. Furthermore, SL fundamentally alters the sequence of thermal unfolding events; β-aggregation precedes helical domain unfolding, suggesting protective binding to BSA’s helical regions. Computational docking reveals high-affinity binding (Kd = 14.5 μM). Uniquely, SL binds between BSA domains IB and IIIA, establishing hydrophobic interactions, salt bridges, and hydrogen bonds, thus stabilizing the protein’s 3D structure. This distinct binding site is attributed to SL’s amphipathic character. This work deepens the understanding of the molecular characteristics of SL–protein interactions and contributes to improving the general knowledge of this outstanding biosurfactant.