Morphology of Lipid Aggregates on Clay Minerals and Connections to Macroscopic Wettability

Abstract

pore between two membranes. Especially vague is the understanding about the role of the transmembrane domains (TMDs) of the SNARE proteins for the establishment of hemi-and full fusion states. Therefore, we propose a new experimental system to investigate the fusogenic role of SNARE TMDs in model lipid membranes. The system consist of an atomic force microscopy (AFM) cantilever with an integrated microfluidic channel, that is used to firstly attach a giant unilamellar vesicle (GUV) to the tip of the cantilever by applying negative pressure inside of the channel, and to subsequently bring this GUV into force-controlled contact with a supported lipid bilayer or a surface immobilized GUV. Using fluorescence measurements we are able to observe fusion states dependent on the contact force, contact time, and other parameters like membrane tension and ion concentration. By bringing two lipid membranes into close and force-controlled proximity, the presented experimental system is able to mimic the zippering function of the cytosolic domains of the SNARE complex. Therefore, the next step will be the inclusion of SNARE TMDs into the phospholipid membranes in varying concentrations and combinations to gain insights into their function within the fusion machinery. Consequently, the proposed experimental system will facilitate new insights into SNARE-mediated fusion and will shed light on the basic principles of neuronal signal transmission. Additionally, this system can also be used to investigate other phenomena related to the interaction of lipid membranes. 1818-PosMeasuring Neutralization of Enveloped Viruses using Microfluidics Understanding the mechanism by which antibody neutralize enveloped viruses is crucial for the advancement of antibody therapeutics as well as for the rational design of new vaccines and antiviral drugs. Influenza antibodies mainly target the head or stem regions of envelope glycoprotein hemagglutinin and function via interfering with the virus-host cell attachment or function of the fusion proteins. Herein, we present a microfluidic platform for parallel testing of multiple antibodies against different viral strains at the single-virus level using fluorescence microscopy. By using both glycan receptors and DNA-based attachment of viruses, we can differentiate antibody neutralization targeting attachment from neutralization that specifically affects fusion. Our DNA tethering strategy in a parallel microfluidic flow cell also paves the way to study the cross-reactivity of broadly neutralizing antibodies for closely related viruses in the same family as well as for the newly emerging viruses with no requirement of specific receptors on the target membrane. Assembly of the lipid fraction of soil organic matter on mineral surfaces may stabilize lipids against microbial attack and the consequent redistribution of carbon. However, such assembly is a poorly understood phenomenon that reflects underlying lipid-lipid and lipid-substrate interactions, both of which are expected to be sensitive to hydration/...