Biochemistry Commons^™

Caulobacter Clpxp Adaptor Popa’S Domain Interactions In The Adaptor Hierarchy Of Ctra Degradation, Thomas P. Scudder

Masters Theses

The degradation and recycling of protein is a process essential for the maintenance and regulation of cellular function. More specifically, in Caulobacter crescentus, the ClpXP protease is responsible for driving progression through the cell cycle and protein quality control. This protease utilizes three known adaptors to selectively degrade proteins that initiate different stages of development. This thesis will elaborate on the specific binding interface on one of these adaptors, PopA, with another, RcdA, and focus in on specific residues on PopA and investigate their roles in adaptor binding and delivery of CtrA, the master regulator of Caulobacter. Finally, I …

Investigating The Helicase Activity Of Methylated Vs Unmethylated Ded1, Hannah Lukow

Honors Theses

Ded1 is an RNA helicase protein of the DEAD-box subfamily in eukaryotic organisms (Sharma & Jankowsky, 2014) which can act as an activator or initiation factor, during translation (Hilliker et al., 2011). Ded1 has several functions in yeast including assembly of translational initiation factors, scanning the mRNA for the start codon, and unwinding any double stranded segments of mRNA with its helicase ability. Ded1 was discovered to be methylated at four arginine sites in vivo (Low et al., 2013), with a fifth methylation site being discovered recently (Low et al., 2020), however the purpose of such post-translational modifications is still …

Characterizing The Roles Of The Variable Linker And Hub Domains In Camkii Activation, Noelle Dziedzic

Doctoral Dissertations

Learning and memory formation at the cellular level involves decoding complex electrochemical signals between nerve cells, or neurons. Understanding these processes at the molecular level requires a comprehensive study of calcium-sensitive proteins that serve as signal mediators within cells. More specifically, the protein calcium/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of downstream cellular signaling events in the brain, playing an important role in long term memory formation. CaMKII is encoded in humans on four different genes: alpha, beta, gamma and delta. For added complexity, each of these gene products can be alternatively spliced and translated into multiple protein …

Computational Investigation Of Calmodulin Photocontrol With The Help Of An Azobenzene Derivative, Jeremy Wells

Undergraduate Honors Theses

The ability to control the activity and binding capability of enzymes in a reversible manner offers tremendous control over biological processes. Photocontrol, in particular, is promising in that electromagnetic radiation can be fine-tuned in terms of its strength, location, and duration. Photosensitive compounds, such as the azobenzene family, experience an isomerization at certain wavelengths, and attaching these compounds to enzymes has the potential to alter their structure and activity. Calmodulin (CaM) is a Ca2+ -sensitive signaling protein that has the ability to affect several downstream processes in eukaryotes and is an excellent target for photocontrol due to its small size …

Retro-Structural Analysis Of The Four Helix Bundle Motif In Binuclear Proteins, Walker Pedigo, Maggie Smith

Honors Theses

Protein structure is directly related to protein function. There are four levels of protein structure: primary, secondary, tertiary, and quaternary. The interactions amongst the structural components of a protein give rise to its unique characteristics. The four helix bundle motif is a common structural trait in a variety of binuclear proteins. In this study, PyMOL, a molecular visualization system, was used to analyze binuclear proteins that possess a four helix bundle. Images of proteins containing dicopper, diiron, and dimanganese sites were captured. The images were compiled into figures for each individual protein. After creating the figures, each protein was further …

Small Heat Shock Protein 27 And Its Role In Human Disease, Bianka Andrea Holguin

Open Access Theses & Dissertations

Small heat shock protein 27 (Hsp27) is a ubiquitously expressed molecular chaperone with roles in many physiological processes. As an ATP-independent molecular chaperone, Hsp27 protects substrates from irreversible aggregation and holds them in a folding competent state for later recycling into the proteome. Hsp27 proteins form dimers that are assembled into large oligomeric complexes. Phosphorylation of Hsp27 dissembles the oligomers into chaperone active dimers. Several missense mutations of Hsp27 are causative for the neurodegenerative disorders Charcot-Marie-Tooth disease 2F and distal Hereditary Motor Neuropathy IIB. Here I show that the oligomerization and chaperoning ability of Hsp27 are altered by the Hsp27 …

Investigating Structural Proteins By Light Scattering, Uma Nudurupati

Masters Theses

This thesis evaluates the organization of the structural proteins, Human Gamma D crystallin and Collagen type II, into higher-order structures using light scattering. Specifically, it evaluates the natures of incipient aggregation in Human Gamma D crystallin and the nature of its interactions with CAPEGn, an electrostatic blocker. Additionally, this thesis evaluates whether Collagen type II growth kinetics follows Classical nucleation theory.

Biophysical Characterization Of The Par-4 Tumor Suppressor: Evidence Of Structure Outside The Coiled Coil Domain And Interactions With Platinum Chemotherapeutics, Andrea Megan Clark

Chemistry & Biochemistry Theses & Dissertations

Prostate apoptosis response-4 (Par-4) is an apoptosis-inducing tumor suppressor protein. Full-length Par-4 has previously been shown to be a predominantly intrinsically disordered protein (IDP) under neutral conditions, with significant regular secondary structure evident only within the C-terminal coiled coil domain. However, IDPs can gain ordered structure through the process of induced folding, which often occurs under non-neutral conditions. Previous work has shown that the Par-4 leucine zipper, which is a subset of the C-terminal coiled coil domain, is disordered under neutral conditions, but forms a dimeric coiled coil at acidic pH. Increase in ionic strength was also shown to increase …

Crystallization Efforts For An Engineered Nickel-Binding Protein, Gold-Bovine Serum Albumin Nanoclusters, And An Artificial De Novo Tetramer Hydrogenase Mimic, Skyler Crane

Honors Theses

Protein crystallization is fundamental to modern research efforts given its ability to determine a protein’s structure as well as the interactions that structure allows and relies upon. This process, though lacking direct application, provides necessary information for subsequent research efforts for which applicationsmay be explored. As such, efforts were taken to crystallize nickel-binding protein (NBP) reengineered from Copper Storage Protein 1 (Csp1) in its apo and metal bound form, Bovine Serum Albumin (BSA) in its apo and gold bound form (Au-BSA), and an artificial de novo tetramer hydrogenase mimic peptide to better inform future research actions for these respective molecules. …

Investigation Of Potentially Catalytic Residues Of Uba5 Through Mutagenesis, Purification, And Structural Characterization, Grant Bradley

Senior Honors Projects, 2020-current

Ubiquitin-fold modifier 1 (Ufm1) is a member of the Ubiquitin (Ub) family of proteins whose primary function is degradation of proteins through a sequential mechanism of chemical reactions. Though Ufm1’s specific roles are largely unknown, this family of proteins has shown to play a part in a wide variety of processes, including regulation of the cell cycle¹, secretory functions of cells^2,3, and blood clotting⁴. Ufm1’s mechanism of action proceeds with the aid of three enzymes: an E1, E2, and E3. Uba5 is the E1 activating enzyme that is specific to Ufm1, and its mechanism of …

Characterization Of Avidin And Case9 Single Protein Molecules By A Solid-State Nanopore Device, Haopeng Li

Graduate Theses and Dissertations

The shape and charge of a protein play significant roles in protein dynamics in the biological system of humans and animals. Characterizing and quantifying the shape and charge of a protein at the single-molecule level remains a challenge. Solid-state nanopores made of silicon nitride (SiNx) have emerged as novel platforms for biosensing such as diagnostics for single-molecule detection and DNA sequencing. SSN detection is based on measuring the variations in ionic conductance as charged biomolecules translocate through nanometer-sized channels driven by an external voltage applied across the membrane. In this paper, we observe the translocation of asymmetric cylindrical structure CRISPR-Cas9 …

A Proteomic Analysis Of Corydoras Sterbai Secretions And Tissues, Erik Powell Wictor

University of the Pacific Theses and Dissertations

Defensive mechanisms vary widely in the animal kingdom ranging from physical defenses like spines to chemical defenses such as toxins. Toxins in these secretions and tissues can fluctuate from enzymes to lipids to uncharacterized chemicals. Next generation -omics technology and mass spectrometry are extremely important in analyzing these samples because of their ability to distinguish minute amounts of toxic substance within a complicated sample. The goal of this experiment was to look at secretions and tissues from Corydoras sterbai. All samples in this study were proteolyzed using a mixture of Trypsin and Lys-C, fractionated, and run through nanoLC-MS/MS analysis using …

Single Molecule Fluorescence Studies Of Protein Structure And Dynamics Underlying The Chloroplast Signal Recognition Particle Targeting Pathway, Dustin R. Baucom

Graduate Theses and Dissertations

The work presented in this dissertation explores the structural dynamics in the chloroplast signal recognition particle pathway. Findings include cpSRP shows scanning functionality similar to that in the cytosolic SRP with the ribosome. The intrinsically disordered C-terminal tail of the Albino3 protein has some transient secondary structure. Upon binding to cpSRP43 in solution, separate secondary structure formation was identified in the C-terminal tail of Albino3. Finally, to increase efficiency of analyzing fluorescence time traces for this work, a modular software was produced.

Synthesis, Stabilization, And Modification Of Zinc Oxide Nanoparticles For Biological Applications, Allison Kimberly Freese

MSU Graduate Theses

Nanoparticles have become very useful as delivery systems in biomedicine. The nanoparticles can be layered with different compounds to produce a vessel for transport of biological materials. Specifically, gold nanoparticles layered with a reducing agent, lysozyme, and polyelectrolytes can be synthesized to transport lysozyme into a cell. However, zinc oxide nanoparticles are cheaper, biocompatible nanoparticles that can be used for the same process. Here in, zinc oxide nanoparticle conjugates were synthesized, modified, and analyzed to be used as a biological material delivery system. The zinc oxide nanoparticles were synthesized using zinc chloride and sodium hydroxide. The particles were then layered …

Protein-Protein Interactions In Perilpin 5, Erin K. Hughes

Undergraduate Honors Thesis Projects

Many metabolic diseases contribute to a major part of the health crisis in the US. Type II diabetes mellitus and non-alcoholic fatty liver disease are two examples of metabolic diseases that are contributing to the current health crisis. Key to understanding these diseases and their progression is an understanding of neutral lipid metabolism. Perilipins are a class of five conserved proteins that are key regulators of lipid metabolism and are potentially involved in lipid trafficking within cells. The most recently discovered member of the family is perilipin 5, which is expressed most strongly in tissues that are highly oxidative such …

Automatic 13C Chemical Shift Reference Correction Of Protein Nmr Spectral Data Using Data Mining And Bayesian Statistical Modeling, Xi Chen

Theses and Dissertations--Molecular and Cellular Biochemistry

Nuclear magnetic resonance (NMR) is a highly versatile analytical technique for studying molecular configuration, conformation, and dynamics, especially of biomacromolecules such as proteins. However, due to the intrinsic properties of NMR experiments, results from the NMR instruments require a refencing step before the down-the-line analysis. Poor chemical shift referencing, especially for ¹³C in protein Nuclear Magnetic Resonance (NMR) experiments, fundamentally limits and even prevents effective study of biomacromolecules via NMR. There is no available method that can rereference carbon chemical shifts from protein NMR without secondary experimental information such as structure or resonance assignment.

To solve this problem, we …

Structural Characterization Of Black Widow Spider Dragline Silk Proteins Crp1 And Crp4, Mikayla Shanafelt

University of the Pacific Theses and Dissertations

Spider dragline silk is a biomaterial with outstanding material properties, possessing high-tensile strength and toughness. In nature, dragline silk serves a central role during spider locomotion and web construction. Today, scientists are racing to elucidate the molecular machinery governing silk extrusion, attempting to translate this knowledge into a mimicry process in the laboratory to create synthetic fibers for a wide range of different applications. During extrusion, it has been established that biochemical and mechanical forces govern spidroin folding, aggregation, and assembly. In black widow spiders, at least 7 different proteins have been identified as constituents of dragline silk fibers. These …

Sers For Protein Detection At A Single Molecule Level For Developing A New Medical Diagnostics Platform, Lamyaa Almehmadi

Legacy Theses & Dissertations (2009 - 2024)

A two-step process of protein detection at a single molecule level using Surface Enhanced Raman Spectroscopy (SERS) was developed as a new platform for medical diagnostics in this proof-of-concept study. First, a protein molecule was bound to a linker in the bulk solution and then this adduct was chemically reacted with the SERS substrate. Traut’s Reagent (TR) was used to thiolate Bovine serum albumin (BSA) in solution followed by chemical cross linking to a gold surface through a sulfhydryl group. A Glycine-TR adduct was used as a control sample to identify the protein contribution to the SER spectra. Gold SERS …

The Distinctive Regulatory Mechanisms Of Bacterial Acetyl-Coa Carboxylase, Alexandra Leigh Evans

LSU Doctoral Dissertations

Metabolic Regulation is a complex system used to control cellular metabolism in response to conditions in the cell’s environment. For most enzymes, the cell can rely upon a minimal amount of regulation; however, critical enzymes, such as acetyl-CoA carboxylase, must be regulated at multiple levels. Acetyl-CoA carboxylase catalyzes the first committed step in fatty acid synthesis. In bacteria, acetyl-CoA carboxylase forms a complex of three subunits–biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase–which catalyze the carboxylation of acetyl-CoA to form malonyl-CoA via two half-reactions. In the first half-reaction, biotin covalently linked to biotin carboxyl carrier protein is carboxylated by biotin …

The N-Terminal Methyltransferase Homologs Nrmt1 And Nrmt2 Exhibit Novel Regulation Of Activity Through Heterotrimer Formation., Jon David Faughn

Electronic Theses and Dissertations

Protein, DNA, and RNA methyltransferases have an ever-expanding list of novel substrates and catalytic activities. Even within families and between homologs, it is becoming clear the intricacies of methyltransferase specificity and regulation are far more diverse than originally thought. In addition to specific substrates and distinct methylation levels, methyltransferase activity can be altered through formation of complexes with close homologs. This work involves the N-terminal methyltransferase homologs NRMT1 and NRMT2. NRMT1 is a ubiquitously expressed distributive trimethylase. NRMT2 is a monomethylase expressed at low levels and in a tissue-specific manner. They are both nuclear methyltransferases with overlapping target consensus sequences …

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …

Caveolin Binding Motif Mutation Yields A Variance In Follicle Stimulating Hormone Receptor Signaling, Justin Fleischer

Honors Theses

The human follicle stimulating hormone receptor (hFSHR) is a glycoprotein hormone receptor belonging to the g protein-coupled receptor family. It is important in both male and female reproductive processes; defects in hFSHR can lead to infertility, delayed puberty, reduced muscle bulk, and osteoporosis. Work in other labs has shown that GPCRs can be localized to microdomains located within the cell membrane called lipid rafts. These regions are highly resistant to detergents because of the high concentration of sphingolipids and cholesterol. Also within these domains, an intracellular protein, caveolin, is present. Our lab has shown that hFSHR also localizes to lipid …

Studies Into The Structure And Function Of Various Domains Of Obscurin And Titin, Rachel A. Policke

Senior Honors Projects, 2010-2019

Muscles give our bodies the ability to move by stretching and contracting. While contraction is accomplished by the well-known actin-myosin interaction, not much is known about stretch. Two integral muscle proteins involved in stretch are titin and obscurin; both are long rope-like protein molecules that seem to act as molecular springs. Mutations in these two proteins can lead to diseases such as hypertrophic cardiomyopathy and muscular dystrophy, as well as a variety of cancers. In an effort to understand muscle stretch and signaling on a more fundamental level, here we present the high resolution structure of obscurin Ig59, a domain …

Inquiry Into Perilipin-5a Expression In Triacylglycerol Rich Vs Normal Fed Mouse Tissue, Kobi Agyepong

Undergraduate Honors Thesis Projects

The steep rise in both childhood and adult obesity over the past three decades has moved to the forefront of public consciousness in recent years. This development has generated a marked increase in general health awareness and lifestyle changes for a vast number of individuals, most notably in the form of increased physical activity and diet alterations. The latter point is especially salient in a biochemical context, because of the myriad factors that can result in “fat accumulation”. Chief among these factors is the Perilipin 5A gene, (known as PLIN5A) which encodes the protein Perilipin 5A of the Perilipin family …

Mutagenic And Spectroscopic Investigation Of Ph Dependent Cooa Dna Binding, Brian R. Weaver

Chemistry Honors Papers

The carbon monoxide (CO) sensing heme protein, CooA, is a transcription factor which exists in several bacteria that utilize CO as an energy source. CooA positively regulates the expression of coo genes in the presence of CO such that the corresponding proteins may metabolize CO. The present studies have yielded the unexpected result that Fe(III) CooA binds DNA tightly at pH < 7, deviating from all previously reported work which indicate that CooA DNA binding is initiated only when the exogenous CO effector reacts with the Fe(II) CooA heme. This observation suggests that the disruption of one or more salt bridges upon effector binding may be a critical feature of the normal CooA activation mechanism. To test this possibility, several protein variants that eliminated a selected salt bridge for the CooA homolog from Rhodospirillum rubrum were prepared via site-directed mutagenesis. Samples of these variant proteins, which were overexpressed in Escherichia coli, were then characterized by spectroscopic methods and functional assays to investigate the impact these mutations had on CooA heme coordination …

Adsorption Of Biomolecules On Carbon-Based Nanomaterial As Affected By Surface Chemistry And Ionic Strength, Peng Du

Doctoral Dissertations

In the first project, we examined adsorption of bovine serum albumin (BSA) and lysozyme (LYZ) on carboxylated (CM), hydroxylated (HM) and graphitized (GM) multi-wall carbon nanotubes (CNTs). All adsorption isotherms were fitted well with Langmuir model. Maximum adsorption capacities (mg/g) followed: HM>CM>GM for both BSA and LYZ, which positively related to the surface areas of the three CNTs. However, after surface area normalization, adsorption capacity (mg/m²) followed: HM>GM>CM for BSA and GM>CM>HM for LYZ, indicating that functional groups and hydrophobicity of CNTs also contributed to protein adsorption. In addition, adsorption of LYZ …

Elucidating Structure, Function, And Small Molecular Interactions Of Human Immunodeficiency Virus And Chikungunya Virus, Kristin Nicole Slater

Wayne State University Theses

Abstract HIV-1:

Human immunodeficiency virus-1 (HIV-1) is a widespread, incurable retrovirus known to cause

immunodeficiency and a shortened life span. Despite successful treatment methods, HIV-1

frequently mutates, resulting in antiviral resistance. Many therapies target the HIV-1 protease

(PR), which is responsible for cleaving the viral polyprotein essential for its life cycle. HIV-1 PR

often evades treatment by way of mutations and less commonly through residue insertions. We

have identified a clinical isolate with a five residue insertion between residues 28 and 29.

Through molecular dynamics simulations we analyzed the protease protein structure and

determined that the residue insertion created a …

Neuronal Gq Structures In Neurodegeneration, Damian S. Mcaninch

Electronic Theses and Dissertations

This study investigates protein nucleic acid interactions between various proteins and G quadruplex (GQ) forming messenger RNAs (mRNAs) in human neurological disorders. GQ structures are formed in DNA/RNA, when four guanine residues form planar tetrads stabilized by Hoogsteen base pairing, that stack forming a GQ structure stabilized by potassium ions. These GQ structures are targeted by the arginine-glycine-glycine (RGG) repeat domain containing RNA-binding domain.

Three RGG domain containing RNA-binding proteins, all of which have been implicated in neurological disorders, and their interactions with GQ forming mRNAs, were investigated in this study: fused in sarcoma (FUS), fragile X mental retardation protein …

Interaction Of Spliceosomal U2 Snrnp Protein P14 With Its Branch Site Rna Target, William Perea Vargas

Dissertations, Theses, and Capstone Projects

Newly transcribed precursor messenger RNA (pre-mRNA) molecules contain coding sequences (exons) interspersed with non-coding intervening sequences (introns). These introns must be removed in order to generate a continuous coding sequence prior to translation of the message into protein. The mechanism through which these introns are removed is known as pre-mRNA splicing, a two-step reaction catalyzed be a large macromolecular machine, the spliceosome, located in the nucleus of eukaryotic cells. The spliceosome is a protein-directed ribozyme composed of small nuclear RNAs (snRNA) and hundreds of proteins that assemble in a very dynamic process. One of these snRNAs, the U2 snRNA, is …

Conformational Dynamics Of Cytochrome P450cam Upon Ligand Binding, Ana Virginia Bernal Gomez

Masters Theses

Cytochrome P450s are a superfamily of metalloenzymes that are responsible for the monooxygenation of their hydrophobic substrates. P450’s retain the same general structural scaffold, however are able to bind promiscuously to substrates with distinct physico-chemical properties. It is believed that they possess considerable flexibility in the substrate binding regions as well as their active site to accomplish the diverse binding and catalytic chemistry with high regio- and stereo-specificity. In order to investigate the conformational dynamics inherent in these enzymes, especially in context of binding different ligands, we carried out amide proton exchange studies via NMR spectroscopy on a model P450 …