Lipid mediated colloidal interactions

The lipid membrane is a basic structural component of all living cells. Embedded in this nanometer-thin barrier, membrane proteins shape the membrane and at the same time respond to the shape of the membrane. This two-way interaction gives rise to a force between membrane-deforming objects that is mediated by the membrane. In this thesis, this effect is measured by employing micron-sized colloidal particles. In Chapters 2 and 3, methods for extracting local forces from video images of colloidal particles are described. Then, in Chapter 4, the development of colloidal particles that strongly attach to specific lipid membranes is described. These are then used in Chapters 5 and 6, in which membrane-mediated forces and assembly pathways between membrane-attached colloidal particles are investigated and quantified. Finally, in Chapters 7 and 8, the preparation of micron-sized oil droplets is studied and their use as lipid monolayer support is demonstrated. The results from this thesis contribute to fundamental microbiological questions about forces between membrane proteins, as well as to the understanding of the toxicity of microplastics. Biological and Soft Matter Physic

Colloidal joints with designed motion range and tunable joint flexibility

Biological and Soft Matter Physic

Colloidal joints with designed motion range and tunable joint flexibility

Biological and Soft Matter Physic

Lipid membrane-mediated attraction between curvature inducing objects

Biological and Soft Matter Physic

Preparation of colloidal organosilica spheres through spontaneous emulsification

Biological and Soft Matter Physic

Discovery of a NAPE-PLD inhibitor that modulates emotional behavior in mice

N-acylethanolamines (NAEs), which include the endocannabinoid anandamide, represent an important family of signaling lipids in the brain. The lack of chemical probes that modulate NAE biosynthesis in living systems hamper the understanding of the biological role of these lipids. Using a high-throughput screen, chemical proteomics and targeted lipidomics, we report here the discovery and characterization of LEI-401 as a CNS-active N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) inhibitor. LEI-401 reduced NAE levels in neuroblastoma cells and in the brain of freely moving mice, but not in NAPE-PLD KO cells and mice, respectively. LEI-401 activated the hypothalamus–pituitary–adrenal axis and impaired fear extinction, thereby emulating the effect of a cannabinoid CB1 receptor antagonist, which could be reversed by a fatty acid amide hydrolase inhibitor. Our findings highlight the distinctive role of NAPE-PLD in NAE biosynthesis in the brain and suggest the presence of an endogenous NAE tone controlling emotional behavior.NWOMicrobial Biotechnolog

Lipid mediated colloidal interactions

The lipid membrane is a basic structural component of all living cells. Embedded in this nanometer-thin barrier, membrane proteins shape the membrane and at the same time respond to the shape of the membrane. This two-way interaction gives rise to a force between membrane-deforming objects that is mediated by the membrane. In this thesis, this effect is measured by employing micron-sized colloidal particles. In Chapters 2 and 3, methods for extracting local forces from video images of colloidal particles are described. Then, in Chapter 4, the development of colloidal particles that strongly attach to specific lipid membranes is described. These are then used in Chapters 5 and 6, in which membrane-mediated forces and assembly pathways between membrane-attached colloidal particles are investigated and quantified. Finally, in Chapters 7 and 8, the preparation of micron-sized oil droplets is studied and their use as lipid monolayer support is demonstrated. The results from this thesis contribute to fundamental microbiological questions about forces between membrane proteins, as well as to the understanding of the toxicity of microplastics. </div