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Articles 1 - 30 of 73
Full-Text Articles in Microbiology
Advancing Biological Applications Through Microfluidic-Based Tool Development, K.M. Taufiqur Rahman
Advancing Biological Applications Through Microfluidic-Based Tool Development, K.M. Taufiqur Rahman
Electronic Theses and Dissertations
This research undertook an interdisciplinary approach, integrating bioengineering, microbiology, molecular biology, and systems biology to investigate bacterial dynamics behavior. Specifically, it delved into the development of microfluidic devices for biological applications such as bacterial cell counts, real-time observation of plant roots (here, specialized lectin-coated microbeads are used that mimic root characteristics), and soil microbe interactions. Furthermore, Next-Generation Sequencing and systems biology methodologies were employed to explore the intricate, multifaceted survival mechanisms of Escherichia coli persister population. Studying and quantifying persisters or testing for the existence of VBNC (viable but nonculturable) is challenging. These experiments require precise counts. It has been …
Next-Generation Sequencing Shows Increasing Temperatures Affect Stream Fungal Communities, Regan Hodgson
Next-Generation Sequencing Shows Increasing Temperatures Affect Stream Fungal Communities, Regan Hodgson
Electronic Theses and Dissertations
Under climate change predictions, surface air temperature is expected to continue to rise and will likely affect functioning of stream ecosystems and microbial communities. Aquatic hyphomycetes are key fungal decomposers of plant litter in headwater streams controlling carbon, energy, and nutrient flows to higher trophic levels. This project addressed the effects of temperature on stream fungal communities in two recently conducted experiments (microcosm and streamside channel studies) using Illumina sequencing. The objectives were to determine (1) if temperature affects community structure of stream fungi based on relative abundances of ITS2 rDNA sequences, (2) if the effects of temperature on aquatic …
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler
Electronic Theses and Dissertations
Microbial communities contain densely packed cells where competition for space and resources are fierce. These communities are generally referred to as biofilms and provide advantages to individual cells against immunological and antimicrobial intervention, dehydration, and predation. High intracellular pools of cyclic diguanylate monophosphate (c-di-GMP) cause cells to aggregate during biofilm formation through the production of diverse extracellular polymers. Genes that encode c-di-GMP catalytic enzymes are commonly mutated during chronic infections where opportunists display enhanced resistance to phagocytosis and antibiotics. Our lab uses an emergent multicellular trait in the model organism Pseudomonas fluorescens Pf0-1 to study the emergence of c-di-GMP mutations …
Leveraging Queueing Theory To Develop Advanced Synthetic Biological Circuits, Prajakta K. Jadhav
Leveraging Queueing Theory To Develop Advanced Synthetic Biological Circuits, Prajakta K. Jadhav
Electronic Theses and Dissertations
The complexity and redundancy in the network topology of the cell hinder our understanding of the natural system, making it challenging to engineer living organisms with the desired functionality. The long-term goal of synthetic biology and bioengineering is to engineer cells to perform specific functions with increased robustness. The robust engineered systems can be easily applied to different species with the same outcome. An effective approach is a bottom-up approach where we tease apart the biological pathways and study them independently. Understanding the underlying mechanisms of biological pathways can be further applied to construct complex biological circuits that function similarly …
Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek
Deciphering The Perpetual Fight Between Virus And Host: Utilizing Bioinformatics To Elucidate The Host's Genetic Mechanisms That Influence Jc Polyomavirus Infection, Michael P. Wilczek
Electronic Theses and Dissertations
JC polyomavirus (JCPyV) is a human-specific pathogen that infects 50-80% of the population, and can cause a deadly, demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). In most of the population, JCPyV persistently infects the kidneys but during immunosuppression, it can reactivate and spread to the central nervous system (CNS), causing PML. In the CNS, JCPyV targets two cell types, astrocytes, and oligodendrocytes. Due to the hallmark pathology of oligodendrocyte lysis observed in disease, oligodendrocytes were thought to be the main cell type involved during JCPyV infection. However, recent evidence suggests that astrocytes are targeted by the virus and act …
Characterizing The Dormancy And Repair Of A Circumneutral Passive Remediation System Receiving Iron And Sulfate-Rich Amd, Garrett Struble
Characterizing The Dormancy And Repair Of A Circumneutral Passive Remediation System Receiving Iron And Sulfate-Rich Amd, Garrett Struble
Electronic Theses and Dissertations
The Wingfield Pines remediation system is a ~20-acre circumneutral, gravity-fed system constructed in 2009 to passively remediate Fe from an ~2000 gallon/minute effluent. In 2017, a fracture to the system’s underground cavern caused the AMD effluent to bypass the system, flowing directly into Chartiers Creek and leaving the system decommissioned between 2017-2019. Soil slurry and water samples were collected in the weeks prior to the system’s reinstalment in September 2019 through January 2020 in order to determine the effect of the repair on remediation efficiency and microbial community composition. This study acted as the first to describe the temporary decommissioning …
Optimized Microbial Recombinant Production Of Hiv-1 Anti-Envelope Antibody Fragments With Applications To Single Particle Tracking Of Virus Assembly, Merissa Michelle Bruns
Optimized Microbial Recombinant Production Of Hiv-1 Anti-Envelope Antibody Fragments With Applications To Single Particle Tracking Of Virus Assembly, Merissa Michelle Bruns
Electronic Theses and Dissertations
In my findings, I have established a set series of protocols to recombinantly produce, purify and apply various fluorescent probes in vitro for the fluorescent labeling and study of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) protein during HIV viral assembly. There remains insufficient knowledge about the molecular dynamics and interactions of HIV-1 Env protein with its counterpart, Gag, on the inner host cell surface during assembly of a mature virus particle. There also remains an insufficient amount of data for the understanding and clarification of the mechanism of action of a known host cell HIV-1 restriction factor, …
Examining The Function Of Protein Acyltransferase Via The Dhhc Domain Of The Paz5 Protein In The Organism Dictyostelium Discoideum, George M. Stuart-Ranchev
Examining The Function Of Protein Acyltransferase Via The Dhhc Domain Of The Paz5 Protein In The Organism Dictyostelium Discoideum, George M. Stuart-Ranchev
Electronic Theses and Dissertations
Protein S-palmitoylation plays a crucial role in many biological systems. S-palmitoylation involves the post-translational attachment of palmitate to a cysteine residue through a reversible thioester linkage. S-Palmitoylation is used to modify both integral and membrane proteins, many of which are involved in intracellular trafficking, membrane localization, and signal transduction pathways. Intracellular palmitoylation is mediated by a family of protein acyltransferases (PATs). PAT mutations are associated with neurological diseases and cancer progression. Proteins in the PAT family are defined by the presence of a 51-amino acid cysteine-rich domain (CRD), which contains a highly conserved aspartate-histidine-histidine-cysteine (DHHC) motif. The …
The Physiology And Evolution Of Selenite Respiration In Bacteria, Michael Wells
The Physiology And Evolution Of Selenite Respiration In Bacteria, Michael Wells
Electronic Theses and Dissertations
The selenium oxyanions selenate (Se(VI)) and selenite (Se(IV)) can be utilized by some bacteria and archaea as terminal electron acceptors in anaerobic respiration. Se(VI) and Se(IV) respiration is mediated by a phylogenetically and ecologically diverse array of organisms, suggesting that selenium respiration is ubiquitous in natural environments. Several respiratory Se(VI) reductases have been characterized in bacteria, revealing that Se(VI) respiration has evolved independently several times in this domain. Se(IV) respiration, in contrast, has yet to be characterized. I have purified and characterized the first respiratory Se(IV) reductase from Bacillus selenitireducens MLS10. The Se(IV) reductase appeared to purify as a single …
Quantification Of Interactions Between Influenza Hemagglutinin And Host Cell Phosphoinositides By Super-Resolution Microscopy, Matthew T. Parent
Quantification Of Interactions Between Influenza Hemagglutinin And Host Cell Phosphoinositides By Super-Resolution Microscopy, Matthew T. Parent
Electronic Theses and Dissertations
The influenza viral membrane protein hemagglutinin (HA) forms dense nanoscale clusters on host cell plasma membranes (PM), but the mechanisms that direct HA clustering are not well understood. Previous studies have observed HA associated with actin rich regions of the PM, but there are no known direct interactions between HA and actin. Phosphatidylinositol 4,5-biphosphate (PIP2) is a signaling lipid in the PM which can regulate the actin cytoskeleton, and actin comets initiated by PIP2 are known to be exploited by HA to reach the PM of infected cells. PIP2 is also used by other viruses, such as HIV and Ebola, …
A Novel Mode Of Action Of C-Reactive Protein In Protecting Against Streptococcus Pneumoniae Infection And Synergy With Antibiotics, Donald Ngwa
Electronic Theses and Dissertations
C-reactive protein (CRP) is a part of the innate immune system, is synthesized in the liver, its blood level increases in inflammatory states, and it binds to Streptococcus pneumoniae. The conformation of CRP is altered under conditions mimicking an inflammatory milieu and this non-native CRP also binds to immobilized/aggregated/pathogenic proteins. Experiments in mice have revealed that one of the functions of CRP is to protect against pneumococcal infection. For protection, CRP must be injected into mice within two hours of administering pneumococci, thus, CRP is protective against early-stage infection but not against late-stage infection. It is unknown how CRP protects …
Molecular Facet Of Host-Pathogen Interactions In Fusarium Head Blight In Wheat ( Triticum Aestivum L.), Bimal Paudel
Molecular Facet Of Host-Pathogen Interactions In Fusarium Head Blight In Wheat ( Triticum Aestivum L.), Bimal Paudel
Electronic Theses and Dissertations
Fusarium head blight (FHB) is a severe disease of wheat (Triticum aestivum L.). It not only reduces the quantity of the harvested grains but also decreases the grain quality due to mycotoxins contamination, especially Deoxynivalenol (DON). Qfhb1 (or simply called Fhb1) is the most important quantitative trait locus (QTL) for FHB resistance. Our lab has previously identified wheat gene WFhb1-1 (aka. Wfhb1_c1) as a candidate for FHB resistance gene. Here we report that WFhb1-1 has been cloned. The gene (GenBank # KU304333.1) consists of a single exon, encoding a putative membrane protein of 127 amino acids. WFhb1-1 protein produced in …
The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga
The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga
Electronic Theses and Dissertations
Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …
The Q Rule In Bacteriodetes And The Identification And Characterization Of Porphyromonas Gingivalis Glutaminyl Cyclase., John Andrew Houston
The Q Rule In Bacteriodetes And The Identification And Characterization Of Porphyromonas Gingivalis Glutaminyl Cyclase., John Andrew Houston
Electronic Theses and Dissertations
Background: Porphyromonas gingivalis, a major pathogen associated with chronic periodontitis, secretes variety of proteins, majority of which begins with glutamine. Several of these proteins were found with pyroglutamate (pGlu) at N-terminus suggesting the presence of this posttranslational modification pathway in P.gingivalis. The observation that N-terminal glutamine is over-represented as the first amino acid after signal peptide cleavage, and subsequent confirmation of pGlu formation on the nascent protein via mass spectrometry, led us to conclude that an enzyme must be present as the executor of this reaction. Hypothesis: PG2157 is a glutaminyl cyclase and is responsible for the cyclization of …
Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer
Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer
Electronic Theses and Dissertations
The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …
Virulence Regulation In Pseudomonas Aeruginosa Via The Alginate Regulators, Algu And Algr, The Posttranscriptional Regulator, Rsma, And The Two-Component System, Algz/R, Sean Stacey
Electronic Theses and Dissertations
Pseudomonas aeruginosa is a Gram-negative bacillus able to colonize a wide variety of environments. In the human host, P. aeruginosa can establish an acute infection or persist and create a chronic infection. P. aeruginosa is able to establish a niche and persist in human hosts by using a wide array of virulence factors used for: movement, killing host cells, and evading immune cells and antibiotics. Understanding virulence factors and their regulation has proved to be an important means of combating the morbidity and mortality of P. aeruginosa as well as the ever-increasing threat of drug resistance. By targeting virulence factors …
Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley
Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley
Electronic Theses and Dissertations
This dissertation examines effects of stress on brown algal biology from a macroscopic scale by examining the whole aquaculture crops, and at a microscopic level by examining the macroalgal microbiome, across the vertical stress gradient of the intertidal zone and across the latitudes of their biogeographic ranges. Thermal stress negatively affected seedstock gametophytes of the kelp Alaria esculenta isolated from northern and southern locations in Maine. However, previous thermal stress had a positive effect on growth of the next-generation sporophytes. Alaria esculenta has potential as a kelp crop in Maine’s sea vegetable aquaculture sector and implementing this protocol may allow …
Superresolved Three-Dimensional Analysis Of The Spatial Arrangement Of The Human Immunodeficiency Virus Type-1 (Hiv-1) Envelope Glycoprotein At Sites Of Viral Assembly, Carmen Anne Buttler
Superresolved Three-Dimensional Analysis Of The Spatial Arrangement Of The Human Immunodeficiency Virus Type-1 (Hiv-1) Envelope Glycoprotein At Sites Of Viral Assembly, Carmen Anne Buttler
Electronic Theses and Dissertations
Human Immunodeficiency Virus type 1 (HIV-1) replicates by forcing infected host cells to produce new virus particles, which assemble form protein components on the inner leaflet of the host cell's plasma membrane. This involves incorporation of the essential viral envelope glycoprotein (Env) into a structural lattice of viral Gag proteins. The mechanism of Env recruitment and incorporation is not well understood. To better define this process, we seek to describe the timing of Env-Gag encounters during particle assembly by measuring angular positions of Env proteins about the surfaces of budding particles. Using three-dimensional superresolution microscopy, we show that Env distributions …
Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru
Electronic Theses and Dissertations
Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …
Characterization Of Porphyromonas Gingivalis Mfa1 Fimbriae., Jae Yong Lee
Characterization Of Porphyromonas Gingivalis Mfa1 Fimbriae., Jae Yong Lee
Electronic Theses and Dissertations
Porphyromonas gingivalis, an obligate anaerobic bacterium associated with chronic periodontitis, utilizes various virulence factors to achieve pathogenicity, one of which is the Mfa1 fimbriae. As a surface structure comprising Mfa1 major subunit along with accessory fimbrial proteins Mfa2-5, the Mfa1 fimbriae has been shown to mediate the adherence of P. gingivalis to antecedent bacterial colonizers of the oral cavity to cause increased virulence. However, the spatial relationships amongst the individual subunits and their assembly mechanism have remained unclear. Through immuno-electron microscopy, Mfa1-4 were localized on the surface of P. gingivalis with Mfa1 localizing throughout the fimbriae and Mfa2 in …
The Synthetic Biology Of N2-Fixing Cyanobacteria For Photosynthetic Terpenoid Production, Charles T. Halfmann
The Synthetic Biology Of N2-Fixing Cyanobacteria For Photosynthetic Terpenoid Production, Charles T. Halfmann
Electronic Theses and Dissertations
In the last few decades, concerns over global climate change, energy security, and environmental pollution have been rising. To overcome these challenges, the concept of “-nth generation” biofuels has emerged as a strategy to convert solar radiation into fuels and bulk industrial chemicals for societal use, while decreasing our consumption of nonrenewable energy sources. Nitrogen-fixing cyanobacteria hold a distinct advantage in biofuel production over plants, given their ability to convert sunlight, air (CO2 and N2), and mineralized water to energy-dense carbon molecules, as well as fix atmospheric nitrogen gas into ammonia for metabolism. Engineered cyanobacteria with …
Dynamic Host-Pathogen Interactions Result In Fungal Epitope Unmasking, Alex Hopke
Dynamic Host-Pathogen Interactions Result In Fungal Epitope Unmasking, Alex Hopke
Electronic Theses and Dissertations
Molecular camouflage is used by a diverse set of pathogens to disguise their identity and avoid recognition by protective host receptors. The opportunistic fungal pathogen Candida albicans is a good example, as it masks the inflammatory component β-glucan in its cell wall to evade detection by the immune receptor Dectin-1. Interestingly, it has been seen that β-glucan becomes unmasked during infection in vivo, though the underlying mechanisms remained unclear. Exposure levels of this epitope may be important, as Dectin-1 mediates protection from some strains of C. albicans and alterations in the organization and composition of the Candida cell wall …
Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely
Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely
Electronic Theses and Dissertations
Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Previous studies indicate that …
Surface Entropy Reduction To Increase The Crystallizability Of The Fab-Rna Complex, Priyadarshini Palaniandy Ravindran
Surface Entropy Reduction To Increase The Crystallizability Of The Fab-Rna Complex, Priyadarshini Palaniandy Ravindran
Electronic Theses and Dissertations
Crystallizing RNA has been an imperative facet and a challenging task in the world of RNA research. Assistive methods such as Chaperone Assisted RNA Crystallography (CARC), employing monoclonal antibody fragments (Fabs) as crystallization chaperones have enabled us to obtain RNA crystal structures by increasing the crystal contacts and providing initial phasing information. Using this technology the crystal structure of [delta]C209 P4-P6 RNA (an independent folding domain of the self-splicing Tetrahymena group I intron) complexed to Fab2 (high affinity binding Fab) has been resolved to 1.95 Å (1). Although the complexed class I ligase ribozyme has also been crystallized using CARC …
Microscopic Analysis Of Sympathetic And Parasympathetic Distribution, Terminal Morphology, And Interaction In Whole-Mount Atria, Scott Harden
Electronic Theses and Dissertations
The sympathetic (SNS) and parasympathetic (PSNS) branches of the autonomic nervous system (ANS) innervate the heart, exerting excitatory and inhibitory influences (respectively) over cardiac functions (heart rate, AV conduction velocity, and contractility). However, the distribution and structure of SNS and PSNS innervation has not yet been well studied. Detailed characterization of the distributional organization and structural morphology of the SNS and PSNS in normal states is essential to the study of pathological autonomic remodeling. The present study utilized double immunohistochemical labeling techniques to examine tyrosine hydroxylase (TH) immunoreactive (IR) SNS and vesicular acetylcholine transporter (VAChT) IR PSNS axons and terminal …
The Expression Of Mkrn1, An E3 Ubiquitin Ligase For Telomerase Reverse Transcriptase, Is Induced With Differentiation Therapy In Leukemia, Jose Salvatico
The Expression Of Mkrn1, An E3 Ubiquitin Ligase For Telomerase Reverse Transcriptase, Is Induced With Differentiation Therapy In Leukemia, Jose Salvatico
Electronic Theses and Dissertations
Telomeres are important structural and functional components of chromosomes, serving to provide stability and enabling full replication of the chromosomes. However, a shortening of the telomeres occurs with each cell division that can be fixed by a polymerase activity provided by telomerase, preventing this loss which would otherwise eventually lead to chromosome end-to-end fusions, senescence and cell death. The telomerase activity is present in stem cells and germ line cells, but absent or barely noticeable in adult somatic cells. However, in approximately 80-90% of transformed somatic cells the telomerase activity is recovered, resulting in a "telomerase positive phenotype". This phenotype …
Mcp-1 And App Involvement Of Glial Differentiation And Migration Of Neuroprogenitor Cells, Emmanuel Vrotsos
Mcp-1 And App Involvement Of Glial Differentiation And Migration Of Neuroprogenitor Cells, Emmanuel Vrotsos
Electronic Theses and Dissertations
Neuroprogenitor cells are an important resource because of their potential to replace damaged cells in the brain caused by trauma and disease. It is of great importance to better understand which factors influence the differentiation and migration of these cells. Previously it has been reported that neuroprogenitor cells undergoing apoptotic stress have increased levels of Amyloid precursor protein (APP) and increased APP expression results in glial differentiation. APP activity was also shown to be required for staurosporine induced glial differentiation of neuroprogenitor cells. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that is expressed during inflammatory. The binding of MCP-1 to …
Vesicle Targeting In Plasmodium Falciparum: The Identification And Molecular Characterization Of Plasmodium Falciparum Family Of Of Snare Proteins, Lawrence Sumanjah Ayong
Vesicle Targeting In Plasmodium Falciparum: The Identification And Molecular Characterization Of Plasmodium Falciparum Family Of Of Snare Proteins, Lawrence Sumanjah Ayong
Electronic Theses and Dissertations
Proteins of the SNARE (Soluble N-ethylmaleimide sensitive factor attachment protein receptor) super-family have been characterized as playing an essential role in vesicle targeting and fusion in all eukaryotes. The intracellular malaria parasite Plasmodium falciparum exhibits an unusual endomembrane system that is characterized by an unstacked Golgi apparatus, a developmentally induced apical complex, and various organellar structures of parasite origin in the infected host cells. How malaria parasites target nuclear-encoded proteins to these novel compartments is a central question in Plasmodium cell biology. Ultrastructural studies elsewhere have implicated the participation of specialized vesicular elements in transport of virulence proteins, including various …
Retrocyclin, A Potent Hiv-1 Entry Inhibitor, Nitya Venkataraman
Retrocyclin, A Potent Hiv-1 Entry Inhibitor, Nitya Venkataraman
Electronic Theses and Dissertations
Human immununodeficiency virus (HIV) infection is the leading cause of death due to viral infections worldwide. In the absence of an effective vaccine or consistent male condom use, there is a clear need for female-controlled preventatives such as topical vaginal microbicides. Recent attention has been focused on developing natural antimicrobial peptides, as anti-retroviral microbicides. Increasing evidence suggests that cationic antimicrobial peptides such as defensins are effective HIV-1 inhibitors. Human alpha- and beta-defensins contribute substantially to innate immune defenses against microbial and viral infections. Certain nonhuman primates also produce theta-defensins – 18 residue cyclic peptides that are potent HIV-1 entry inhibitors. …
Structure-Function Analysis Of Endoproteolytic Cleavage: Site-Directed Mutagenesis Studies Of The Α-Msh Cleavage Site In Silurana Tropicalis Pomc, Quinn Kun Chen
Electronic Theses and Dissertations
The maturation process of many prohormone molecules typically requires endoproteolytic cleavage C-terminal of dibasic residues, such as the K141R142↓ site N-terminal of the α-melanocyte stimulating hormone (α-MSH) sequence in Silurana tropicalis proopiomelanocortin (POMC). In order to determine the absolute requirement of basic amino acid residues in the cleavage process, site-directed mutagenesis was employed to substitute alanine for the wild-type residues in the frog POMC open reading frame. Specifically, the following underlined residues were individually targeted for alanine substitution: R 137 Q 138 E 139 N 140 K 141 R 142↓. The mouse pancreatic αTC1.9 cell …