• Deutsch
    • English
  • English 
    • Deutsch
    • English
  • Login
Item View 
  •   Home
  • Naturwissenschaften, Mathematik und Informatik
  • Fakultät für Physik (inkl. GAUSS)
  • Item View
  •   Home
  • Naturwissenschaften, Mathematik und Informatik
  • Fakultät für Physik (inkl. GAUSS)
  • Item View
JavaScript is disabled for your browser. Some features of this site may not work without it.

Minimal models for lipid membranes: local modifications around fusion objects

by Giovanni Marelli
Doctoral thesis
Date of Examination:2013-01-21
Date of issue:2013-02-01
Advisor:Prof. Dr. Marcus Müller
Referee:Prof. Dr. Marcus Müller
Referee:Prof. Dr. Bert de Groot
crossref-logoPersistent Address: http://dx.doi.org/10.53846/goediss-3698

 

 

Files in this item

Name:Report.pdf
Size:18.3Mb
Format:PDF
Description:Dissertation
ViewOpen

The following license files are associated with this item:


Abstract

English

Solvent-free soft coarse-grained models are particularly appropriate to investigate collective phenomena in lipid membranes. In this work we exploit such a model to show how modifying a few model parameters we can control the bending rigidity of the membrane, the hydration repulsion, and the macroscopic phases of self-assembled structures. Further, we investigate the lipid mediated interactions between fusion objects: transmembrane proteins, pores and stalks. The presence of such defects induces a perturbation in the shape of the membrane and in the conformations of lipids. The modi cations induced by single defects superimpose and for some defect interaction (peptide-peptide, pore-peptide) we identify the equilibrium distance between these objects. The prediction of the results of the simulations are compared with the numerical solution of a continuum model parametrized from the analysis of the simulation snapshots. The presence of transmembrane proteins with a large hydrophobic mismatch weakens the membrane over the direct interaction range decreasing slightly the membrane thickness. This involves the lowering of the line tension of the pore and for a particular number and spatial arrangement of proteins the line tension of the pore is negative and the pore is stable in tensionless membranes. Another agent that in uences the line tension of the pore is oil (short hydrophobic chains). The oil has a con guration space larger than the one of the lipids and partitions to relax the frustration of the lipids at the interfaces and increases the line tension of the pore (the membrane is more resistant under lateral tension). The model parameters have a large in uence on the equilibrium properties of a stalk and we study the characteristic sizes of stalks depending on the hydration between two opposed bilayers and compare the results to other simulation models and experimental data. We show how hydration and lateral tension in uence bilayer repulsion and how the combined e ect of both contributions leads to membrane fusion.
Keywords: Lipid membranes; Molecular Dynamics; Coarse-grained; Monte Carlo; Membrane fusion
 

Statistik

Publish here

Browse

All of eDissFaculties & ProgramsIssue DateAuthorAdvisor & RefereeAdvisorRefereeTitlesTypeThis FacultyIssue DateAuthorAdvisor & RefereeAdvisorRefereeTitlesType

Help & Info

Publishing on eDissPDF GuideTerms of ContractFAQ

Contact Us | Impressum | Cookie Consents | Data Protection Information
eDiss Office - SUB Göttingen (Central Library)
Platz der Göttinger Sieben 1
Mo - Fr 10:00 – 12:00 h


Tel.: +49 (0)551 39-27809 (general inquiries)
Tel.: +49 (0)551 39-28655 (open access/parallel publications)
ediss_AT_sub.uni-goettingen.de
[Please replace "_AT_" with the "@" sign when using our email adresses.]
Göttingen State and University Library | Göttingen University
Medicine Library (Doctoral candidates of medicine only)
Robert-Koch-Str. 40
Mon – Fri 8:00 – 24:00 h
Sat - Sun 8:00 – 22:00 h
Holidays 10:00 – 20:00 h
Tel.: +49 551 39-8395 (general inquiries)
Tel.: +49 (0)551 39-28655 (open access/parallel publications)
bbmed_AT_sub.uni-goettingen.de
[Please replace "_AT_" with the "@" sign when using our email adresses.]