HIV-1 Vpu Oligomerization in Membrane Mimetics

HIV-1 is a pandemic virus that has a continuing impact on human society. As treatments for HIV-1 infection improve, new targets for viral inhibition have provided a means to reduce a once-lethal infection into a manageable chronic condition. Among other proteins, HIV-1 encodes the Vpu accessory protein which upregulates the process of viral release from infected cells, providing an enticing target for future anti-HIV-1 therapies. In this thesis, I outline a conserved AxxAxxxAxxxA motif responsible for the assembly of Vpu into its functional oligomeric form, probe the importance of conserved residues in the motif via mutagenesis, and assess the relative stability of each resulting Vpu complex. Utilizing dynamic light scattering experiments, I characterized the molecular size of the Vpu oligomer in sodium dodecyl sulfate (SDS) solutions. To examine the Vpu oligomeric complex in greater detail, I employed the use of explicit all-atom simulations of the Vpu transmembrane domain oligomer in a hydrated lipid bilayer, verified the importance of the conserved AxxAxxxAxxxA motif, and characterized the stability of several Vpu oligomeric arrangements both in the presence and absence of water channels. Finally, I utilized NMR techniques to probe the Vpu assembly in SDS, dodecyl phosphocholine, and lipid membrane mimetics, providing a comparison between these three environments, and propose further studies based on the results of solution state NMR and solid-state magic angle spinning NMR experiments. The findings of this work are interpreted in the context of Vpu oligomerization relative to previous molecular dynamics simulations, the effect of membrane mimetic environment, and implications for Vpu interactions with host cell target proteins.

Department dc:contributor.department

Biochemistry

Year dc:date.issued

2018

Author dc:creator

• Davidson, David

Advisor dc:contributor.advisor

• Sharpe, Simon J

• HIV
• Membrane Protein
• NMR
• Oligomer
• Vpu

Handle dc:identifier.uri

http://hdl.handle.net/1807/89673

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/89673