Mechanism of C -Cadherin Binding: Multiple Adhesive Alignments and a Multi-Stage Unbinding Trajectory

Abstract

A preliminary characterization of the structure of membrane supported C-cadherin monolayers, that are used in the surface force measurements, is presented in the latter part of the thesis. Using ellipsometry, we monitor the binding of C-cadherin to lipid monolayers in real time. These data suggest that in the presence of calcium, cadherin forms adhesive complexes on lipid monolayers, and these complexes are disrupted by calcium removal. Using x-ray reflectivity, we measure preliminary electron density profiles of the C-cadherin layers and their supporting lipids, normal to the air-water interface. These electron density profiles are used to estimate the dimensions of the cadherin and the lipid monolayers. The thickness of the lipid monolayer and the cadherin extracellular region measured using x-ray reflectivity shows a good agreement with the steric thickness of these layers determined by direct force measurements.