Related Experiment Video
Updated: Jan 9, 2026

On-Chip Octanol-Assisted Liposome Assembly for Bioengineering
Published on: March 17, 2023
Beyond the oil-water interface: Cooperative alkali-lipase catalysis induces pH-responsive self-assembly in triolein
M Frigerio1, M E Leser1, S Salentinig1
1Department of Chemistry, and Food Research and Innovation Center, University of Fribourg, Chemin Du Musée 9, 1700 Fribourg, Switzerland.
Abstract:
Lipase-catalyzed and alkaline hydrolysis of triglycerides generate amphiphilic molecules that reorganize oil-water interfaces and form supramolecular assemblies with defined colloidal properties in oil and water. Here, we present a structural and compositional analysis of a biphasic triolein/buffer system subjected to alkaline treatment or enzymatic hydrolysis by Sus scrofa, Rhizomucor miehei, and Thermomyces lanuginosus lipases across a pH range of 7.0-11.0. Small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS) reveal minimal structural changes below pH 9.0. In contrast, at pH 11.0, reaction-driven self-assembly produces water-in-oil emulsions and vesicles in the oil phase. In the aqueous phase, oil-swollen micelles and vesicles form, with size and morphology dependent on the hydrolysis conditions. These nanostructures correlate with variations in product composition and interfacial enrichment, markedly increasing the available interfacial area. While previous studies have examined lipase-catalyzed lipid hydrolysis, the coupled structural evolution of both oil and aqueous under enzymatic and alkaline conditions has, to the best of our knowledge, not been resolved. This study reveals a direct link between hydrolysis, amphiphile generation, and pH-dependent self-assembly beyond the oil-water interfaces. It offers mechanistic insight relevant to lipid digestion, interfacial catalysis, and the design of pH-responsive colloidal materials.
More Related Videos
Related Concept Videos
Colloids
Cooperative Allosteric Transitions
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
Lipids as Anchors
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...
Asymmetric Lipid Bilayer

