Quantitative Analysis of Cryo-EM Reconstruction of Liposomes and Membrane Proteins [electronic resource].

9781369066067

1 online resource (117 p.)

Access is available to the Yale community.

Cryoelectron microscopy (Cryo-EM) of biological molecules has rapidly grown into an important approach to understand the structure of biological macrocomplexes at the molecular level. Here I describe two quantitative explorations that may improve this technology in the aspects of structure determination and membrane electrophysiology: (1) I implement likelihood-based iterative reconstructions of spherically-constrained single particles to solve the structure of a membrane protein, the G1uA2/AMPA-subtype glutamate receptor, at a resolution comparable to conventional algorithms. This implementation not only reduces the computational cost in three dimensional angle determinations by applying geometric constraints to noisy projection images, it also allows us to solve a membrane protein structure in a lipid membrane, which is its physiological environment. (2) I establish a novel method to estimate membrane potential from phase-plate cryo-EM images. With the ongoing development of phase-plate Cryo-EM, our computational method could potentially visualize the membrane potential in situ when we determine the structure of a voltage-sensing protein in a lipid vesicle. Both algorithms can be applied to similar systems with a spherical constraint.

Books / Online / Dissertations & Theses

English

January 19, 2017

Thesis (Ph.D.)--Yale University, 2016.