Related Experiment Video
Updated: Nov 17, 2025
Incorporating Target Protein Structure Flexibility and Dynamics in Computational Drug Discovery Using Ensemble-Based Docking Analysis
Published on: June 20, 2025
Characterization of substrate specificity and inhibitory mechanism of bile salt hydrolase from Lactobacillus reuteri
Ana Estela Ledesma1, María Pía Taranto2, Ana Yanina Bustos3,4,5
1Departamento Académico de Química, Facultad de Ciencias Exactas y Tecnologías, Centro de Investigación en Biofísica Aplicada y Alimentos (CIBAAL-UNSE-CONICET), Universidad Nacional de Santiago del Estero, Av. Belgrano Sur 1912, 4200, Santiago del Estero, Argentina.
Objectives:
To elucidate the molecular mechanisms involved in the substrate interaction of the bile salt hydrolase of Lactobacillus reuteri CRL 1098 (LrBSH) with bile acids (BAs) and to evaluate potential enzyme inhibitors based on computer and in vitro modeling assays.
Results:
Asp19, Asn79, and Asn171 participated in the LrBSH interaction with all BAs tested while Leu56 and Glu 222 played an important role in the interaction with glyco- and tauro-conjugated BAs, respectively. A great percentage of hydrophobic and polar interactions were responsible for the binding of LrBSH with glyco- and tauro-conjugated BAs, respectively. Remarkably, the four binding pocket loops participated in the substrate binding site of LrBSH unlike most of the reported BSHs. Inhibition assays showed that ascorbic acid, citric acid, penicillin G, and ciprofloxacin decreased LrBSH activity by 47.1%, 40.14%, 28.8%, and 9%, respectively. Docking analysis revealed that tetracycline and caffeic acid phenethyl ester had the low binding energy (-7.32 and -7.19 kcal/mol, respectively) and resembled the interaction pattern of GDCA (-6.88 kcal/mol) while penicillin (-6.25 kcal/mol) and ascorbic acid (-5.98 kcal/mol) interacted at a longer distance.
Conclusion:
This study helps to delve into the molecular mechanisms involved in the recognition of substrates and potential inhibitors of LrBSH.
