Supervisors: André Schroder and Carlos Marques
My PhD is a contribution towards the understanding of the role played by biomacromolecules in the formation of the adhesive contact between bio-functional phospholipid membranes. We study the spreading of a biotinylated DOPC bilayer on a carpet of double end-grafted !-phage DNAs. The spreading process scrapes and staples the chains between the membrane and the substrate. The final stapled DNA shape is a function of both the internal chain tension and the forces applied by the bilayer. We show that by using the well known force extension relationship for a DNA molecule we can reveal the forces at play during the formation of the adhesion patch. We also compute the monomer distribution of the segments of the DNA chains that are not confined under the membrane but emerge from the membrane side and fluctuate within the geometric boundaries of the system. Finally we control the conformations and the dynamics of the tethered DNAs by using AzoTAB, a photosensitive compacting agent of the DNA chains.
PhD Manuscript avalaible here 