Related Experiment Video
Updated: Jan 20, 2026

SA-β-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs
Published on: June 28, 2019
Quillaja bark saponin effects on Kluyveromyces lactis β-galactosidase activity and structure
Cíntia Tiemi Misugi Kayukawa1, Marco Aurélio Schüler Oliveira2, Elaine Kaspchak1
1Department of Chemical Engineering, Federal University of Paraná (UFPR), Polytechnic Center, Jardim das Américas, 81531-990 Curitiba, PR, Brazil.
Abstract:
Saponins are known for their bioactive and surfactant properties, showing applicability to the food, cosmetic and pharmaceutical industries. This work evaluated the saponins effects on Kluyveromyces lactis β-galactosidase activity and correlated these changes to the protein structure. Enzyme kinetic was evaluated by catalytic assay, protein structure was studied by circular dichroism and fluorescence, and isothermal titration calorimetry was used to evaluate the interactions forces. In vitro enzymatic activity assays indicated an increase in the protein activity due to the saponin-protein interaction. Circular dichroism shows that saponin changes the β-galactosidase secondary structure, favoring its protein-substrate interaction. Besides, changes in protein microenvironment due to the presence of saponin was observed by fluorescence spectroscopy. Isothermal titration calorimetry analyses suggested that saponins increased the affinity of β-galactosidase with the artificial substrate o-nitrophenyl-β-galactoside. The increase in the enzyme activity by saponins, demonstrated here, is important to new products development in food, cosmetic, and pharmaceutical industries.
More Related Videos
Related Concept Videos
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme...
Structure-Activity Relationships and Drug Design
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence...
Cholinergic Antagonists: Chemistry and Structure-Activity Relationship
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of...
Local Anesthetics: Chemistry and Structure-Activity Relationship
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...

