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Full-Text Articles in Medicine and Health Sciences

Predicting Biomolecular Properties And Interactions Using Numerical, Statistical And Machine Learning Methods, Elyssa Sliheet Apr 2024

Predicting Biomolecular Properties And Interactions Using Numerical, Statistical And Machine Learning Methods, Elyssa Sliheet

Mathematics Theses and Dissertations

We investigate machine learning and electrostatic methods to predict biophysical properties of proteins, such as solvation energy and protein ligand binding affinity, for the purpose of drug discovery/development. We focus on the Poisson-Boltzmann model and various high performance computing considerations such as parallelization schemes.


The Power And Challenge Of Lipid (A)Symmetry Across The Membrane And Cell, Mikhail Bogdanov Mar 2023

The Power And Challenge Of Lipid (A)Symmetry Across The Membrane And Cell, Mikhail Bogdanov

Journal Articles

Membrane asymmetry means that the two sides of membrane are structurally, physically and functionally different. Membrane asymmetry is largely related to the lipid sidedness and particularly to compositional (lipid head and acyl group) and physical (lipid packing order, charge, hydration and H-bonding interactions) differences in the inner and outer leaflets of lipid bilayer. Chemically, structurally and conformationally different non-covalent bound lipid molecules are physically fluid and deformable and enable to interact dynamically to form transient arrangements with asymmetry both perpendicular and parallel to the plane of the lipid bilayer. Although biological membranes are almost universally asymmetric however the asymmetry is …


Imaging Nanoscale Plasma Membrane Dynamics Reveals Diversity In Clathrin-Coated Vesicle Formation, Tomasz Jacek Nawara Jan 2023

Imaging Nanoscale Plasma Membrane Dynamics Reveals Diversity In Clathrin-Coated Vesicle Formation, Tomasz Jacek Nawara

All ETDs from UAB

Clathrin-mediated endocytosis (CME) is an essential cellular process facilitating the internalization of a variety of cargo. Clathrin polymerization and changes in plasma membrane architecture and composition are necessary steps to mediate the formation of clathrin-coated vesicles (CCVs). However, simultaneous analysis of clathrin dynamics and membrane structure in living cells is challenging due to the limited axial resolution of fluorescence microscopes and the heterogeneity of CME. This has fueled conflicting models of vesicle assembly and obscured the roles of flat clathrin assemblies. Here we use Simultaneous Two-wavelength Axial Ratiometry (STAR) microscopy to bridge this critical knowledge gap by quantifying the nanoscale …


Investigating Bzip Recognition Of Dna Sequences Through A Knob-Socket Perspective, Aaron Tran Jan 2023

Investigating Bzip Recognition Of Dna Sequences Through A Knob-Socket Perspective, Aaron Tran

University of the Pacific Theses and Dissertations

To investigate whether higher order packing interactions confer protein-DNA specificity, a modified Knob-Socket (KS) model was used to analyze the interface of bZIP-DNA crystal structures. The KS analysis identified a nine-residue quadripartite recognition core consisting of four contiguous KS pockets P1, P2, N3, and N4 that each pack one of the four DNA half-site bases in the target sequence. Only one base per base pair packs, and these interactions are split across the DNA strands: the first two positive strand positions 1p and 2p pack into P1 and P2 while the last two negative strand positions 3n and 4n pack …


Preparation Of Zein-Based Nanoparticles : Nanoprecipitation Versus Microfluidic-Assisted Manufacture, Effects Of Pegylation On Nanoparticle Characteristics And Cellular Uptake By Melanoma Cells, Jitkasem Meewan, Sukrut Somani, Jamal Almowalad, Partha Laskar, Margaret Mullin, Graeme Mackenzie, Swapnil Khadke, Yvonne Perrie, Christine Dufès Jun 2022

Preparation Of Zein-Based Nanoparticles : Nanoprecipitation Versus Microfluidic-Assisted Manufacture, Effects Of Pegylation On Nanoparticle Characteristics And Cellular Uptake By Melanoma Cells, Jitkasem Meewan, Sukrut Somani, Jamal Almowalad, Partha Laskar, Margaret Mullin, Graeme Mackenzie, Swapnil Khadke, Yvonne Perrie, Christine Dufès

School of Medicine Publications and Presentations

Background: The manufacture of nanoparticles using manual methods is hampered by its challenging scaleup and poor reproducibility. To overcome this issue, the production of zein nanoparticles entrapping a lipophilic drug model, coumarin-6, by using a microfluidic system was assessed in this study. The influence of PEG density and chain length on zein nanoparticle characteristics, as well as their uptake efficacy in melanoma cancer cells, was also evaluated.

Methods: Zein nanoparticles were prepared by both manual and microfluidic approaches to allow comparison between the two processes. PEGylated zein nanoparticles with various PEG densities and chain lengths were produced by …


Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair May 2022

Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair

Dissertations & Theses (Open Access)

KRAS, a 21 kDa small GTPase protein, functions as a molecular switch playing a key role in regulating cell proliferation. Dysregulation of KRAS signaling by oncogenic mutations leads to uncontrolled cell proliferation, a hallmark of cancer cells. Attempts to therapeutically target oncogenic KRAS have led to limited success resulting in a need to identify new mechanisms to targeting KRAS. The interaction of KRAS with its regulators, effectors, and the membrane present one such avenue. In this study, we investigated how post-translational covalent and environmental modifications could modulate these interactions of KRAS. Using computational molecular dynamics simulations, nuclear magnetic resonance spectroscopy …


Abhd5 Induced Morphological Changes On Model Membrane Systems, Nasser S. Junedi May 2021

Abhd5 Induced Morphological Changes On Model Membrane Systems, Nasser S. Junedi

Honors College Theses

Proper regulation of neutral lipid storage (lipogenesis) and release (lipolysis) are critical molecular processes localized to an organelle called the Lipid Droplet (LD). The LD consists of a core with neutral lipids such as triacylglycerols (TAGs) and sterol esters surrounded by a phospholipid monolayer. Dysregulation of the processes localized to the LD are involved in the pathology of various diseases such as Neutral Lipid Storage Disease, diabetes, stroke and cancer. The non-enzymatic protein ABHD5 (α-β Hydrolase Domain-Containing Protein 5), is thought to play a key role in the process of lipolysis by forming homo-oligomers on the surface of the LD …


Zero Balancing In The Chiropractic Practice, Michele Doucette Dc Apr 2021

Zero Balancing In The Chiropractic Practice, Michele Doucette Dc

Journal of Transformative Touch

Discovering the profound gifts of the leading-edge structural and energetic manual therapy Zero Balancing (ZB), and adding it to my chiropractic and nutrition practice, has unified my personal growth with the sustainability of my professional practice. Much of humanity is starving for wholeness, authenticity, and meaningful connection with ourselves, others, and something greater. Chiropractors are well positioned to be leaders in a true evolution of healthcare, especially if, as we continue to explore the various branches of our therapeutic repertoires, we stay connected to our vitalistic roots that are now more supported than ever by new findings in the fields …


Evaluating The Energetics Of Entrainment In A Human–Machine Coupled Oscillator System, Ryan T. Schroeder, James L. Croft, John E. A. Bertram Jan 2021

Evaluating The Energetics Of Entrainment In A Human–Machine Coupled Oscillator System, Ryan T. Schroeder, James L. Croft, John E. A. Bertram

Research outputs 2014 to 2021

During locomotion, humans sometimes entrain (i.e. synchronize) their steps to external oscillations: e.g. swaying bridges, tandem walking, bouncy harnesses, vibrating treadmills, exoskeletons. Previous studies have discussed the role of nonlinear oscillators (e.g. central pattern generators) in facilitating entrainment. However, the energetics of such interactions are unknown. Given substantial evidence that humans prioritize economy during locomotion, we tested whether reduced metabolic expenditure is associated with human entrainment to vertical force oscillations, where frequency and amplitude were prescribed via a custom mechatronics system during walking. Although metabolic cost was not significantly reduced during entrainment, individuals expended less energy when the oscillation forces …


Simulation Of A Rat Muscle-Tendon Unit With Hill-Type Model Dynamics And The Study Of Viscoelasticity In A Collagen Molecule Via Molecular Dynamics, Veronica Siko Jan 2021

Simulation Of A Rat Muscle-Tendon Unit With Hill-Type Model Dynamics And The Study Of Viscoelasticity In A Collagen Molecule Via Molecular Dynamics, Veronica Siko

West Chester University Master’s Theses

The field of biological science has established that tendons transfer muscular forces to adjacent bones, but there is a dearth of information about the underlying physical principles of these interactions and how the property of viscoelasticity (displayed in tendons as a difference in mechanical response to stress with differing stretching rates) is encompassed in the collagen of tendons. This thesis details the results of concentric and eccentric contractions of the rat muscle-tendon unit (MTU) with and without viscoelasticity (concentric contraction requires active shortening of the muscle, while eccentric contraction requires active lengthening of the muscle) (Lovering & Brooks, 2014). Once …


Quantifying Anticancer Drug Doxorubicin Binding To Dna Using Optical Tweezers, Zachary Ells Dec 2020

Quantifying Anticancer Drug Doxorubicin Binding To Dna Using Optical Tweezers, Zachary Ells

Honors Program Theses and Projects

Doxorubicin is a successful anticancer drug approved for use in the 1970s and is considered to be one of the most effective cancer treatment methods today. Although Doxorubicin has positive survival statistics it has very negative side effects in many cases. Bleeding from the soles of the palms and feet, along with excruciating pain is often exhibited through the administration of this drug. Based on the preliminary findings utilizing optical tweezers we anticipate that this study will provide critical information about the drug binding mechanism. Single molecule biophysics techniques have provided useful insight into the DNA-binding mechanisms of small molecules. …


Functional Analysis Of A Critical Glycine (Glycine 12) In Beta-Type Connexins Of Human Skin, Rasheed Bailey May 2020

Functional Analysis Of A Critical Glycine (Glycine 12) In Beta-Type Connexins Of Human Skin, Rasheed Bailey

Biology Theses

At least five beta-type connexins are expressed in various layers of the skin (Cx26, Cx30, Cx30.3, Cx31, and Cx32) and all include a glycine residue at position 12. Glycine12 (G12) is located about halfway through the cytoplasmic amino terminus and has been the focus of several studies related to connexin diseases and gap junction channel structure. The importance of this residue is evident in the severity and diversity of diseases associated with amino acid substitutions at G12 including hereditary forms of skin disease, deafness and neuropathy. This study uses bioinformatic analysis in combination with mutational analysis and electrophysiology to better …


Clincial Translational Science Research Of The Functional Role Of Large Conductance Potassium Channels In Selective Destruction Of Triple Negative Breast Cancer Cells, Gina Sizemore Jan 2020

Clincial Translational Science Research Of The Functional Role Of Large Conductance Potassium Channels In Selective Destruction Of Triple Negative Breast Cancer Cells, Gina Sizemore

Graduate Theses, Dissertations, and Problem Reports

ABSTRACT

The preliminary background that puts this research into context is threefold; it is the aggressive nature of triple negative breast cancer (TNBC), the complexity surrounding its pathology, and the significant lack of targeted treatment for this disease. To clarify the focus of my research, I have concentrated on identifying a targeted treatment for TNBC. In the process, I have identified cycles of reciprocity between treatment, clinical diagnosis, staging, and pathology that will be addressed in smaller papers. However, the weight of this work is in the discovery of a novel target for triple negative breast cancer. The value of …


Giardia Lamblia Growth In Viscoelastic Fluids, Kelly Watanabe Jan 2019

Giardia Lamblia Growth In Viscoelastic Fluids, Kelly Watanabe

CMC Senior Theses

Giardia lamblia is a single-celled protozoan parasite that when ingested, causes diarrheal disease and infects 33% of people in developing countries. Previous studies observe Giardia in water-like fluids, but Giardia's infectious environment consists of viscoelastic mucus in the small intestine. Therefore, Giardia was cultured in viscoelastic fluids, and its population growth was observed in vitro. To create shear-thinning viscoelastic fluids, 0.2% and 0.4% long-chain polyacrylamide (LCPAM) was added to cell culture media. Giardia was cultured in control media, 0.2% LCPAM, and 0.4% LCPAM, and population growth was quantitatively determined over time. Increasing LCPAM concentration resulted in a solution with …


Structure Based Drug Design Of High Affinity Kras Inhibitors, Michael Mccarthy May 2018

Structure Based Drug Design Of High Affinity Kras Inhibitors, Michael Mccarthy

Dissertations & Theses (Open Access)

RAS, one of the most well characterized membrane-associated small GTPases, is a notorious oncogene with >15% of all tumors harboring RAS mutations. When RAS is mutated it becomes constitutively active sending cell growth, survival and proliferation into overdrive, which subsequently leads to cancer. Although, RAS has been aggressively targeted with drug design efforts for more than 30 years an FDA approved direct inhibitor has not yet been developed. There are three isoforms of RAS in cells; HRAS, NRAS and KRAS. We focused on KRAS since it is the most frequently mutated isoform in cancer. To identify novel non-covalent small molecules …


Fret-Based Investigations Of The Structure-Function Relationships In The Nmda Receptor, Drew M. Dolino May 2017

Fret-Based Investigations Of The Structure-Function Relationships In The Nmda Receptor, Drew M. Dolino

Dissertations & Theses (Open Access)

The N-methyl-D-aspartate (NMDA) receptor is one member of a class of proteins known as the ionotropic glutamate receptors. Ionotropic glutamate receptors mediate the majority of excitatory neurotransmission in the central nervous system, with the NMDA receptor standing out among these receptors for its requirement of a co-agonist, its magnesium-block-based coincidence detection, its slow kinetics, its calcium permeability, its allosteric modulation, and its especially important functional roles in synaptic plasticity, excitotoxicity, and more. In recent years, a wealth of structural information has come about describing endpoint structures to high resolution, but such structures are unable to fully resolve the movements …


Oncolog, Volume 61, Number 09, September 2016, Jill Delsigne-Russell, Brandon C. Strubberg, E Nielsen Sep 2016

Oncolog, Volume 61, Number 09, September 2016, Jill Delsigne-Russell, Brandon C. Strubberg, E Nielsen

OncoLog MD Anderson's Report to Physicians (All issues)

  • Transport Oncophysics Could Guide Pancreatic Cancer Treatment: Pancreatic ductal adenocarcinomas respond poorly to standard treatments. Researchers at The University of Texas MD Anderson Cancer Center are applying the principles of physics to characterize the tumors, and these analyses could lead to individualized therapy.
  • Nivolumab Shows Potential in Treating Squamous Cell Carcinoma of the Anal Canal: Currently, there are no standard therapy options for patients with treatment-refractory metastatic squamous cell carcinoma of the anal canal (SCCA), but early results of a multi-institutional clinical trial (No. NCI9673) led by researchers at The University of Texas MD Anderson Cancer Center show that the …


Associative Spike Timing-Dependent Potentiation Of The Basal Dendritic Excitatory Synapses In The Hippocampus In Vivo., Thomas K Fung, Clayton S Law, L Stan Leung Jun 2016

Associative Spike Timing-Dependent Potentiation Of The Basal Dendritic Excitatory Synapses In The Hippocampus In Vivo., Thomas K Fung, Clayton S Law, L Stan Leung

Physiology and Pharmacology Publications

Spike timing-dependent plasticity in the hippocampus has rarely been studied in vivo. Using extracellular potential and current source density analysis in urethane-anesthetized adult rats, we studied synaptic plasticity at the basal dendritic excitatory synapse in CA1 after excitation-spike (ES) pairing; E was a weak basal dendritic excitation evoked by stratum oriens stimulation, and S was a population spike evoked by stratum radiatum apical dendritic excitation. We hypothesize that positive ES pairing-generating synaptic excitation before a spike-results in long-term potentiation (LTP) while negative ES pairing results in long-term depression (LTD). Pairing (50 pairs at 5 Hz) at ES intervals of -10 …


Transient Pupil Dilation After Subsaccadic Microstimulation Of Primate Frontal Eye Fields., Sebastian J Lehmann, Brian D Corneil Mar 2016

Transient Pupil Dilation After Subsaccadic Microstimulation Of Primate Frontal Eye Fields., Sebastian J Lehmann, Brian D Corneil

Brain and Mind Institute Researchers' Publications

UNLABELLED: Pupillometry provides a simple and noninvasive index for a variety of cognitive processes, including perception, attention, task consolidation, learning, and memory. The neural substrates by which such cognitive processes influence pupil diameter remain somewhat unclear, although cortical inputs to the locus coeruleus mediating arousal are likely involved. Changes in pupil diameter also accompany covert orienting; hence the oculomotor system may provide an alternative substrate for cognitive influences on pupil diameter. Here, we show that low-level electrical microstimulation of the primate frontal eye fields (FEFs), a cortical component of the oculomotor system strongly connected to the intermediate layers of the …


Chemically Related 4,5-Linked Aminoglycoside Antibiotics Drive Subunit Rotation In Opposite Directions, Michael R. Wasserman, Arto Pulk, Zhou Zhou, Roger B. Altman, John C. Zinder, Keith D. Green, Sylvie Garneau-Tsodikova, Jamie H. Doudna Cate, Scott C. Blanchard Jul 2015

Chemically Related 4,5-Linked Aminoglycoside Antibiotics Drive Subunit Rotation In Opposite Directions, Michael R. Wasserman, Arto Pulk, Zhou Zhou, Roger B. Altman, John C. Zinder, Keith D. Green, Sylvie Garneau-Tsodikova, Jamie H. Doudna Cate, Scott C. Blanchard

Pharmaceutical Sciences Faculty Publications

Dynamic remodelling of intersubunit bridge B2, a conserved RNA domain of the bacterial ribosome connecting helices 44 (h44) and 69 (H69) of the small and large subunit, respectively, impacts translation by controlling intersubunit rotation. Here we show that aminoglycosides chemically related to neomycin-paromomycin, ribostamycin and neamine-each bind to sites within h44 and H69 to perturb bridge B2 and affect subunit rotation. Neomycin and paromomycin, which only differ by their ring-I 6'-polar group, drive subunit rotation in opposite directions. This suggests that their distinct actions hinge on the 6'-substituent and the drug's net positive charge. By solving the crystal structure of …


Registered Report: Biomechanical Remodeling Of The Microenvironment By Stromal Caveolin-1 Favors Tumor Invasion And Metastasis, Steven Fiering, Lay-Hong Ang, Judith Lacoste, Tim D. Smith, Erin Griner Jul 2015

Registered Report: Biomechanical Remodeling Of The Microenvironment By Stromal Caveolin-1 Favors Tumor Invasion And Metastasis, Steven Fiering, Lay-Hong Ang, Judith Lacoste, Tim D. Smith, Erin Griner

Dartmouth Scholarship

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replicating selected results from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012 were selected on the basis of citations and Altimetric scores (Errington et al., 2014). This Registered report describes the proposed replication plan of key experiments from ‘Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis’ by Goetz and colleagues, published in Cell in 2011 (Goetz et al., 2011). The key experiments …


Risperidone And Its Deconstructed Analogs: Functional Effects On The 5ht2ar, Sneha Shah May 2015

Risperidone And Its Deconstructed Analogs: Functional Effects On The 5ht2ar, Sneha Shah

Sneha Shah

G protein-coupled receptors (GPCRs) are seven-transmembrane domain receptors that sense extracellular signal and activate intracellular signaling pathways. The serotonin 5HT2A receptor (or 2AR) is one of the GPCRs coupled to Gq proteins, activating PLC and hydrolyzing PIP2. This hydrolysis causes a diffusion of bound PIP2 away from the channel binding site resulting in G protein-gated inwardly rectifying K+ channel (GIRK) inhibition and a downstream stimulation of Ca2+ release from endoplasmic reticulum stores. Previous experiments have demonstrated that the serotonin 5HTA receptor is a target of serotonergic psychedelic drugs, such as LSD, and partially mediates the action of many atypical antipsychotic …


Risperidone And Its Deconstructed Analogs: Functional Effects On The 5ht2ar, Sneha Shah Jan 2015

Risperidone And Its Deconstructed Analogs: Functional Effects On The 5ht2ar, Sneha Shah

Theses and Dissertations

G protein-coupled receptors (GPCRs) are seven-transmembrane domain receptors that sense extracellular signal and activate intracellular signaling pathways. The serotonin 5HT2A receptor (or 2AR) is one of the GPCRs coupled to Gq proteins, activating PLC and hydrolyzing PIP2. This hydrolysis causes a diffusion of bound PIP2 away from the channel binding site resulting in G protein-gated inwardly rectifying K+ channel (GIRK) inhibition and a downstream stimulation of Ca2+ release from endoplasmic reticulum stores. Previous experiments have demonstrated that the serotonin 5HTA receptor is a target of serotonergic psychedelic drugs, such as LSD, and partially mediates the action of many …


Permeation Redux: Thermodynamics And Kinetics Of Ion Movement Through Potassium Channels., Richard Horn, Benoît Roux, Johan Aqvist May 2014

Permeation Redux: Thermodynamics And Kinetics Of Ion Movement Through Potassium Channels., Richard Horn, Benoît Roux, Johan Aqvist

Department of Molecular Physiology and Biophysics Faculty Papers

The fundamental biophysics underlying the selective movement of ions through ion channels was launched by George Eisenman in the 1960s, using glass electrodes. This minireview examines the insights from these early studies and the explosive progress made since then.


Early Integration Of The Individual Student In Academic Activities: A Novel Classroom Concept For Graduate Education In Molecular Biophysics And Structural Biology, Sanford H. Leuba, Sean M. Carney, Elizabeth M. Dahlburg, Rebecca J. Eells, Harshad Ghodke, Naveena Yanamala, Grant Schauer, Judith Klein-Seetharaman Jan 2014

Early Integration Of The Individual Student In Academic Activities: A Novel Classroom Concept For Graduate Education In Molecular Biophysics And Structural Biology, Sanford H. Leuba, Sean M. Carney, Elizabeth M. Dahlburg, Rebecca J. Eells, Harshad Ghodke, Naveena Yanamala, Grant Schauer, Judith Klein-Seetharaman

Faculty of Science, Medicine and Health - Papers: part A

Background: A key challenge in interdisciplinary research is choosing the best approach from a large number of techniques derived from different disciplines and their interfaces.

Results: To address this challenge in the area of Biophysics and Structural Biology, we have designed a graduate level course to teach students insightful use of experimental biophysical approaches in relationship to addressing biological questions related to biomolecular interactions and dynamics. A weekly seminar and data and literature club are used to compliment the training in class. The course contains wet-laboratory experimental demonstration and real-data analysis as well as lectures, grant proposal preparation and assessment, …


Molecular Imaging To Target Transplanted Muscle Progenitor Cells, Kelly Gutpell, Rebecca Mcgirr, Lisa Hoffman Mar 2013

Molecular Imaging To Target Transplanted Muscle Progenitor Cells, Kelly Gutpell, Rebecca Mcgirr, Lisa Hoffman

Anatomy and Cell Biology Publications

Duchenne muscular dystrophy (DMD) is a severe genetic neuromuscular disorder that affects 1 in 3,500 boys, and is characterized by progressive muscle degeneration(1, 2). In patients, the ability of resident muscle satellite cells (SCs) to regenerate damaged myofibers becomes increasingly inefficient(4). Therefore, transplantation of muscle progenitor cells (MPCs)/myoblasts from healthy subjects is a promising therapeutic approach to DMD. A major limitation to the use of stem cell therapy, however, is a lack of reliable imaging technologies for long-term monitoring of implanted cells, and for evaluating its effectiveness. Here, we describe a non-invasive, real-time approach to evaluate the success of myoblast …


Using Biophysics And Dynamic Energy Budget Theory To Investigate How A Large Mammal Responds To Varying Environmental Conditions, J A. Roberts, Salm Kooijman, G C. Coulson, A J. Munn, M R. Kearney Jan 2013

Using Biophysics And Dynamic Energy Budget Theory To Investigate How A Large Mammal Responds To Varying Environmental Conditions, J A. Roberts, Salm Kooijman, G C. Coulson, A J. Munn, M R. Kearney

Faculty of Science, Medicine and Health - Papers: part A

Abstract of paper that presented at SICB 2013 Annual Meeting.


Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore Jan 2012

Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) is a signal transduction pathway that couples phosphoryl transfer to active sugar transport across the cell membrane. The PTS is initiated by the binding of phosphoenolpyruvate (PEP) to the C-terminal domain (EIC) of enzyme I (EI), a highly conserved protein that is common to all sugar branches of the PTS. EIC exists in a dynamic monomer/dimer equilibrium that is modulated by ligand binding and is thought to regulate the overall PTS. Isolation of EIC has proven challenging, and conformational dynamics within the EIC domain during the catalytic cycle are still largely unknown. Here, we present …


Comparisons Of Three Analytical Techniques For Measuring Absolute And Relative Temperature Changes During Ultrasound Treatment, Michael G. Miller Apr 2011

Comparisons Of Three Analytical Techniques For Measuring Absolute And Relative Temperature Changes During Ultrasound Treatment, Michael G. Miller

Dissertations

Ultrasound is a thermal modality that utilizes acoustic energy to promote heating. While there are many factors that affect heating of body tissues, the effects of skinfold thickness and skin temperature upon ultrasound heating have not been studied extensively. In addition, while temperature typically follows a linear trend, past research typically uses ANOVA or regression analysis to examine this relationship; but these models examine the within-subject effects (time) and between effects (usually groups) at the group level, not the individual level. Therefore, the purposes of this study are to determine if skin temperature and skinfold thickness are predictors for intramuscular …


Rna-Dependent Selenocysteine Biosynthesis In Eukaryotes And Archaea, Sotiria Palioura May 2010

Rna-Dependent Selenocysteine Biosynthesis In Eukaryotes And Archaea, Sotiria Palioura

Yale Medicine Thesis Digital Library

Selenocysteine (Sec), the 21st genetically encoded amino acid, is the major metabolite of the micronutrient selenium. Sec is inserted into nascent proteins in response to a UGA codon. The substrate for ribosomal protein synthesis is selenocysteinyl-tRNASec. While the formation of Sec-tRNASec from seryl-tRNASec by a single bacterial enzyme selenocysteine synthase (SelA) has been well described, the mechanism of Sec-tRNASec formation in archaea and eukaryotes remained poorly understood. Herein, biochemical and genetic data provide evidence that, in contrast to bacteria, eukaryotes and archaea utilize a different route to Sec-tRNASec that requires the tRNASec-dependent conversion of O-phosphoserine (Sep) to Sec. In this …