Hydrodynamics and Diffusion of Membrane Proteins to Engineer Chemical Reactions in Synthetic Biomembrane Platforms

Supported lipid bilayers (SLBs) have been used to characterize biological phenomena in membranes and to engineer those phenomena for applications such as sensing and separations. While microfluidic SLB platforms have developed considerably recently, extending the capabilities of such platforms for use in mimicking and engineering enzymatic reactions requires progress in a few different areas. These areas include an understanding of transport phenomena in lipid bilayers, the incorporation of transmembrane proteins into SLBs, the fluidization of those transmembrane proteins, and the spatial patterning of SLBs containing different biological materials. Some of the progress made in these areas is described here. First, improvements in SLB technologies are described. A platform in which material from outer membrane vesicles of Escherichia coli cells is incorporated into a SLB is characterized. The activity of an antibacterial compound on the SLB is consistent with previous studies of its activity on the outer membrane, showing that the platform recapitulates important features of the outer membrane. Next, the partial fluidization of transmembrane proteins in supported bilayers formed from mammalian cell blebs is described. The orientation and diffusion of proteins within these bilayers are characterized. Next, computational studies of diffusion of transmembrane proteins are described. The long-time diffusivity of a single transmembrane protein interacting with a random array of immobilized transmembrane proteins via both hydrodynamic and thermodynamic interactions is characterized. Next, the same model is used to characterize the effect of immobile proteins on the diffusive mode of a single mobile protein. Results from these two studies appear to be consistent with experimental work. Afterwards, a Brownian dynamics simulation method is described which includes 2D hydrodynamic interactions relevant for transmembrane proteins. Finally, efforts to use SLBs to engineer enzymatic reactions in a defined sequence are described. The transfer of a glycan from a lipid scaffold to a soluble protein using a transmembrane enzyme embedded in a SLB is demonstrated. Progress in synthesizing the ganglioside GM1 via sequential enzymatic addition of two sugar monomers is then described. In conclusion, additional steps needed to achieve the development of a microfluidic SLB platform to carry out sequential enzymatic reactions are discussed.

Name thesis:degree_name

Ph. D., Chemical Engineering

Level thesis:degree_level

Doctor of Philosophy

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

Cornell University

Year dc:date.issued

2023

Author dc:creator

• Singh, Rohit

Committee members dc:contributor.committeemember

• Koch, Donald
• Feigenson, Gerald

Language dc:language.iso

en

DOI

https://doi.org/10.7298/7xfy-3r58

Dc Identifier Other

ProQuest Submission ID: 13579
ProQuest Publication ID: 30426040

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/114144