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Full-Text Articles in Life Sciences

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield May 2023

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …


A Dna-Peptide Crosslink (Dpc) Increases Mutagenicity In Sos-Induced Escherichia Coli, Alessandra Bassani May 2023

A Dna-Peptide Crosslink (Dpc) Increases Mutagenicity In Sos-Induced Escherichia Coli, Alessandra Bassani

Honors Scholar Theses

Bacteria, such as Escherichia coli, have an inducible system in response to DNA damage termed the SOS response. This system is activated when the replicative DNA polymerase (Pol) III encounters a lesion, uncouples from DNA helicase, and single-stranded DNA (ssDNA) accumulates at the replication fork. In this study, we investigated DNA-peptide crosslink (DpC), a common lesion that results from cross-linking of proteins or peptides, UV irradiation, and alkylating agents. To increase survival following formation of a lesion, the SOS response can utilize homologous recombination, translesion synthesis (TLS), or excision repair. With TLS, the levels of DNA Pol II, IV, …


Analyzing Inhibitors Of The Sars-Cov-2 Endoribonuclease Nsp15, Mary Staunton Mar 2022

Analyzing Inhibitors Of The Sars-Cov-2 Endoribonuclease Nsp15, Mary Staunton

Honors Scholar Theses

The global pandemic caused by the virus SARS-CoV-2 has devastated the world. A flurry of research into the structures and activities of the virus have identified several viable targets for drug therapy, including the endoribonuclease nsp15, also known as EndoU. EndoU has been shown to play a role in diminishing the host cell’s immune response to the virus by cleaving signaling dsRNA, specifically targeting uridine sequences. The development of the crystal structure nsp15 allowed our lab along with others to perform virtual screenings to identify inhibitors that might be able to dock at the active site and inhibit the activity …


Synphilin-1 And Its Effects On Pathogenesis Of Parkinson’S Disease, Mirghani Mohamed Jun 2021

Synphilin-1 And Its Effects On Pathogenesis Of Parkinson’S Disease, Mirghani Mohamed

Honors Scholar Theses

Parkinson's Disease (PD) is a progressive neurodegenerative and movement disorder primarily caused by the degradation of dopaminergic neurons. Known markers of neurodegeneration in PD are Lewy Bodies, which are fibrillar aggregates that are found in the brains of PD patients. Lewy Bodies can accumulate from specific mutations in the SNCA gene that codes for alpha-synuclein, a protein enriched in presynaptic neurons. A mutated SNCA gene can cause conformational aggregates of alpha-synuclein to form toxic species mediating neuronal death. Research into alpha-synuclein has led to the discovery of a binding partner known as synphilin-1 that is also found in protein aggregates …


Reeling In New Antibiotics: Synthesis And Antimicrobial Susceptibility Testing Of Zinc-Binding Clavanins From Styela Clava (Sea Squirt), Eduardo Badillo-Colberg May 2021

Reeling In New Antibiotics: Synthesis And Antimicrobial Susceptibility Testing Of Zinc-Binding Clavanins From Styela Clava (Sea Squirt), Eduardo Badillo-Colberg

Honors Scholar Theses

Clavanins have been a quite rarely studied antimicrobial peptide (AMP) family. Though the data in the few studies published on the matter and in theoretical experimental data presented by the Wang lab in their peptide library creation [14], in that the members of this family could potentially be quite effective novel antimicrobial candidates. Among those that have been targets of studies, Clavanin A has been at the forefront of this endeavor of finding effective novel antimicrobial peptides[14]. In these aforementioned studies, Clavanin A has been shown to be quite effective against many different bacterial strains, which begs the question as …


Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff Dec 2020

Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff

Honors Scholar Theses

Mechanotransduction is the process by which a mechanical stimulus is converted to a cellular signal. This process is heavily influential of cell morphology, differentiation, and behavior. However, altered levels of mechanical stimuli are also found in many pathological contexts. For example, cancerous cells have stiffer surrounding tissue than healthy cells, and research suggests that this alters cell behavior and promotes metastasis. Despite these findings, the cellular processes behind these signaling alterations remain widely unknown. Understanding these cascades is critical, as involved proteins can give us a deeper understanding of the role of mechanotransduction, and certain proteins can potentially be targeted …


The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne May 2015

The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne

Honors Scholar Theses

Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the …


Developing Crosslinking Constructs Of Protein Kinase R, Prisma E. Lopez Jun 2014

Developing Crosslinking Constructs Of Protein Kinase R, Prisma E. Lopez

Honors Scholar Theses

Protein Kinase R (PKR) is a key component of the innate immune antiviral response. PKR is activated upon binding to dsRNA. However, recent studies have shown that PKR can also bind to and become activated by duplex RNAs containing complex secondary structure. The mechanism of PKR binding and activation by these RNAs is currently not known. The approach taken here to determine the mechanism of PKR binding by these RNAs is through the development of PKR constructs that are capable of covalently binding to RNAs. Constructs were created by site-specific incorporation of an unnatural, photoactivatable amino acid within PKR. These …


Mutagenesis Of 8-Oxoguanine Adjacent To An Abasic Site In Escherichia Coli Cells Proficient Or Deficient In Dna Polymerase Iv, Savas T. Tsikis May 2014

Mutagenesis Of 8-Oxoguanine Adjacent To An Abasic Site In Escherichia Coli Cells Proficient Or Deficient In Dna Polymerase Iv, Savas T. Tsikis

Honors Scholar Theses

It is well established that clustered DNA damages or multiply damaged sites (MDS) are the result of ionizing radiation and that they are characterized by an enhanced mutagenic potential. As a model MDS, we have evaluated the mutagenic and cytotoxic properties of the ubiquitous oxidative DNA damage 8-oxoguanine (G8-oxo) adjacent to the abasic site lesion (Z) using a single stranded M13mp7L2 vector. The recombinant DNA was used to transform wild type E. coli strains and strains deficient in the translesion DNA polymerase of the Y-family, DNA polymerase IV, in the presence or absence of SOS induction. The percent …


Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer May 2014

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

Honors Scholar Theses

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …


Characterization Of Udp-Arabinopyranose Mutase Genes In The Arabidopsis Cell Wall Mutant Mur5, Christopher A. Hart May 2014

Characterization Of Udp-Arabinopyranose Mutase Genes In The Arabidopsis Cell Wall Mutant Mur5, Christopher A. Hart

Honors Scholar Theses

The genome of Arabidopsis thaliana contains several coding regions for UDP-arabinopyranose mutases (UAMs) that are also known as reversibly glycosylated polypeptides (RGPs). The mur5 cell wall mutant of Arabidopsis shows a 30% decrease in cell wall arabinose content, and a missense mutation in the Reversibly Glycosylated Polypeptide 2 gene was recently proposed to cause this mutant phenotype. Through a traditional complementation analysis, mur5 and a T-DNA insertion mutant in the RGP2 gene were shown not to complement each other, indicating that the two genes are mutant alleles of the same locus. The mur5 SNP located in RGP2 caused a more …


Methyl Septanoside Hydrolysis As A Measure Of Carbohydrate Ring Flexibility: Substrate Synthesis And Kinetics Analysis, Shawn Michael Miller May 2009

Methyl Septanoside Hydrolysis As A Measure Of Carbohydrate Ring Flexibility: Substrate Synthesis And Kinetics Analysis, Shawn Michael Miller

Honors Scholar Theses

A number of seven-membered ring systems have been found to have promising enzyme inhibiting properties. The common explanation for their efficacy is the apparent improved flexibility that the ring-system has over smaller rings. In an attempt to probe the validity of this hypothesis, unnatural seven-membered ring carbohydrates have been generated and subjected to kinetics analysis using hydrolysis. In particular, methyl α- and β-D-glycero-D-guloseptanoside were subjected to acid-catalyzed hydrolysis and monitored via HNMR experiments. The rate constants of the reactions were determined and compared to the hydrolysis rate constants of comparable pyranose carbohydrates and found to be significantly faster, indicating an …