Model Membranes and Their Interactions with Native and Artificial Lipoproteins

Sammanfattning: Atherosclerosis arises from build-up of plaque in the blood, can result in cardiovascular disease and is the largest killer in the west. Low- and high-density lipoproteins are involved in the disease development by depositing and removing lipids to and from artery walls. These processes are complex and not fully understood however, therefore determining the specific roles of the components involved is of fundamental importance in the treatment of the disease.The work presented in this thesis investigates the production of recombinant tailor-deuterated cholesterol, the structure of cholesterol-containing model membranes and interactions of both native and reconstituted lipoproteins with model membranes. Deuteration is commonly used in neutron scattering for biological samples to provide highly important contrast and the complexity of the native lipoproteins leads to the use of more simple model systems where the compositions can be altered and investigated systematically.A protocol was developed to produce matchout-deuterated cholesterol for use in neutron scattering studies, as cholesterol is a hugely important component in membranes. The verification of the matchpoint of cholesterol was determined by small-angle neutron scattering and the localisation of cholesterol in model membranes was determined through the use of neutron reflectometry. The interactions of the native and reconstituted lipoproteins with model membranes were also followed by neutron reflectometry, while the structural characterisation of the reconstituted lipoproteins was carried out by small-angle scattering.