Life Sciences Commons^™

Development And Application Of Mass Spectrometry-Based Protein Footprinting In Structural Proteomics, Ming Cheng

Arts & Sciences Electronic Theses and Dissertations

Integral mass spectrometry (MS) has emerged as an important tool for protein structural characterization. It readouts are a broad range of structural information, including stoichiometry, interactions, conformations and conformation change, and dynamics. Protein footprinting is a pivotal component in the intergral MS toolkit.My dissertation centers around the development and application of protein footprinting to characterize protein structure. It is divided into seven chapters.Chapter 1 serves as the introduction for integral mass spectrometry in structural proteomic.In Chapter 2, we extended the fast-photochemical oxidation of proteins (FPOP) platform by adding the trifluoromethyl radical (•CF3) as a new reagent. We discovered that •CF3 …

Quantitatively Studying Tissue Damage In Multiple Sclerosis Using Gradient Recalled Echo Mri Sequences, Biao Xiang

Arts & Sciences Electronic Theses and Dissertations

Multiple Sclerosis (MS) is an unpredictable, often disabling disease of the central nervous system (CNS) that disrupts the flow of information within the brain, and between the brain the body. MS is the most common progressive neurologic disease of young adults, affecting approximately 2.3 million people worldwide. It is estimated that more than 700,000 individuals are affected by MS in United States. While MS has been studied for decades, the cause of it is still not definite and a fully effective treatment for MS is not yet available. Magnetic resonance imaging (MRI) has been used extensively in MS diagnosis and …

Fast-Forward Protein Folding And Design: Development, Analysis, And Applications Of The Fast Sampling Algorithm, Maxwell Isaac Zimmerman

Arts & Sciences Electronic Theses and Dissertations

Molecular dynamics simulations are a powerful tool to explore conformational landscapes, though limitations in computational hardware commonly thwart observation of biologically relevant events. Since highly specialized or massively parallelized distributed supercomputers are not available to most scientists, there is a strong need for methods that can access long timescale phenomena using commodity hardware. In this thesis, I present the goal-oriented sampling method, Fluctuation Amplification of Specific Traits (FAST), that takes advantage of Markov state models (MSMs) to adaptively explore conformational space using equilibrium-based simulations. This method follows gradients in conformational space to quickly explore relevant conformational transitions with orders of …

Quantitatively Studying Tissue Damage In Multiple Sclerosis Using Gradient Recalled Echo Mri Sequences, Biao Xiang

Arts & Sciences Electronic Theses and Dissertations

Multiple Sclerosis (MS) is an unpredictable, often disabling disease of the central nervous system (CNS) that disrupts the flow of information within the brain, and between the brain the body. MS is the most common progressive neurologic disease of young adults, affecting approximately 2.3 million people worldwide. It is estimated that more than 700,000 individuals are affected by MS in United States. While MS has been studied for decades, the cause of it is still not definite and a fully effective treatment for MS is not yet available.

Magnetic resonance imaging (MRI) has been used extensively in MS diagnosis and …

Mechanism Of Activation Of Uvrd Helicase By A Processivity Factor Mutl, Yerdos Ordabayev

Arts & Sciences Electronic Theses and Dissertations

E. coli UvrD is a superfamily 1A helicase/translocase involved in DNA repair, recombination, and replication. I investigated the role of E. coli MutL, a regulatory protein involved in methyl-directed mismatch DNA repair, in the regulation of UvrD-catalyzed DNA unwinding. Using single molecule fluorescence resonance energy transfer (FRET) and single round stopped-flow DNA unwinding experiments I demonstrated that MutL can activate latent UvrD monomer helicase activity and also stimulate UvrD dimer helicase activity. Furthermore, using analytical ultracentrifugation experiments I determined that a single MutL dimer is sufficient to activate UvrD monomer helicase. DNA unwinding experiments with a series of DNA substrates …

Mechanism Of Activation Of Uvrd Helicase By A Processivity Factor Mutl, Yerdos Ordabayev

Arts & Sciences Electronic Theses and Dissertations

E. coli UvrD is a superfamily 1A helicase/translocase involved in DNA repair, recombination, and replication. I investigated the role of E. coli MutL, a regulatory protein involved in methyl-directed mismatch DNA repair, in the regulation of UvrD-catalyzed DNA unwinding. Using single molecule fluorescence resonance energy transfer (FRET) and single round stopped-flow DNA unwinding experiments I demonstrated that MutL can activate latent UvrD monomer helicase activity and also stimulate UvrD dimer helicase activity. Furthermore, using analytical ultracentrifugation experiments I determined that a single MutL dimer is sufficient to activate UvrD monomer helicase. DNA unwinding experiments with a series of DNA substrates …

A Physics-Based Intermolecular Potential For Biomolecular Simulation, Joshua Andrew Rackers

Arts & Sciences Electronic Theses and Dissertations

The grand challenge of biophysics is to use the fundamental laws of physics to predict how biological molecules will move and interact. The atomistic HIPPO (Hydrogen-like Intermolecular Polarizable Potential) force field is meant to address this challenge. It does so by breaking down the intermolecular potential energy function of biomolecular interactions into physically meaningful components (electrostatics, polarization, dispersion, and exchangerepulsion) and using this function to drive molecular dynamics simulations. This force field is able to achieve accuracy within 1 kcal/mol for each component when compared with ab initio Symmetry Adapted Perturbation Theory calculations. HIPPO is capable of this accuracy because …

Force Requirements And Force Generation During Endocytosis In Yeast, Jonah Kyle Scher-Zagier

Arts & Sciences Electronic Theses and Dissertations

Endocytosis is a process by which cells bring external materials into the intracellular environment and perform other essential biological functions. The main drivers of endocytosis include clathrin and actin, which help shape the membrane and form the endocytic invagination. In mammalian cells and other cells lacking a wall, the primary barriers to endocytosis are the bending rigidity of the cell membrane and surface tension. However, in cells with a rigid cell wall, such as those of yeast, this process is opposed by a substantial pressure within the cell, known as the turgor pressure, which is generated by a difference in …

Modeling Mechanisms Behind Force Generation By Actin Polymerization, Seyed Fowad Motahari

Arts & Sciences Electronic Theses and Dissertations

Actin polymerization is the primary mechanism for overcoming the large turgor pressure that opposes endocytosis in yeast. While generation of pushing forces by actin polymerization is fairly well understood, it is not clear how actin polymerization produces pulling forces. In order to understand this process, it is necessary to simulate polymerization of filaments having various types of interactions with the membrane. Since existing methodologies in the literature do not treat such problems correctly, we develop a thermodynamically consistent methodology for treating polymerization of filaments having arbitrary interaction potentials with the membrane. Then I perform stochastic simulations for a system of …