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Full-Text Articles in Life Sciences

Comparative Animal Mucomics, Antonio R. Cerullo Feb 2024

Comparative Animal Mucomics, Antonio R. Cerullo

Dissertations, Theses, and Capstone Projects

Mucus is one of Nature’s most abundant and versatile biomaterials. These secretions are present in all animals, from the lowly garden snail to the great blue whale, and fulfill a multitude of functions, acting as antimicrobial barriers, moisturizers, adhesive glues, surface lubricants, and mineralizing agents. Despite their importance, very little is known about mucus compositions or properties. The largest challenge precluding the greater understanding of mucus function is its complexity; a single mucus contains complex mixtures of proteins, glycans, and ions that all have important roles in function. Therefore, understanding mucus function necessitates analysis that compares different mucus from one …


Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations, Dhwanit Rahul Dave Feb 2024

Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations, Dhwanit Rahul Dave

Dissertations, Theses, and Capstone Projects

The challenge of establishing a sustainable and circular economy for materials in medicine and technology necessitates bioinspired design. Nature's intricate machinery, forged through evolution, relies on a finite set of biomolecular building blocks with through-bond and through-space interactions. Repurposing these molecular building blocks requires a seamless integration of computational modeling, design, and experimental validation. The tools and concepts developed in this thesis pioneer new directions in peptide-materials design, grounded in fundamental principles of physical chemistry. We present a synergistic approach that integrates experimental designs and computational methods, specifically molecular dynamics simulations, to gain in-depth molecular insights crucial for advancing the …


Characterization Of The Conformational Binding Of N-Methyl Mesoporphyrin Ix With Dna Model Telomeric G-Quadruplex Forming Sequences, Jessica Desamero Sep 2023

Characterization Of The Conformational Binding Of N-Methyl Mesoporphyrin Ix With Dna Model Telomeric G-Quadruplex Forming Sequences, Jessica Desamero

Dissertations, Theses, and Capstone Projects

DNA G-quadruplexes are alternative secondary structures formed from guanine rich DNA sequences. G-quadruplexes are found most abundantly at the ends of chromosomes called telomeres, where they can ultimately prevent further tumor growth and progression. Thus, quadruplex interactive agents, or ligands that can bind to and stabilize DNA G-quadruplex structures, are of high interest for their potential chemotherapeutic abilities. One quadruplex interactive agent is the porphyrin N-methyl mesoporphyrin IX (NMM), which has high binding selectivity for quadruplex structures. While the NMM-quadruplex complex in crystallized form has been greatly studied, this complex in solution form is not as well studied. Through circular …


Construction And Performance Optimization Of Bioconjugated Nanosensors For Early Detection Of Breast Cancer And Pro-Inflammatory Diseases, Pooja Gaikwad Sep 2023

Construction And Performance Optimization Of Bioconjugated Nanosensors For Early Detection Of Breast Cancer And Pro-Inflammatory Diseases, Pooja Gaikwad

Dissertations, Theses, and Capstone Projects

In recent years, nanosensors have emerged as a tool with strong potential in medical diagnostics. Single-walled carbon nanotube (SWCNT) based optical nanosensors have notably garnered interest due to the unique characteristics of their near-infrared fluorescence emission, including tissue transparency, photostability, and various chiralities with discrete absorption and fluorescence emission bands. Additionally, the optoelectronic properties of SWCNT are sensitive to the surrounding environment, which makes them suitable for in vitro and in vivo biosensing. Single-stranded (ss) DNA-wrapped SWCNTs have been reported as optical nanosensors for cancers and metabolic diseases. Breast cancer and cardiovascular diseases are the most common causes of death …


Magnetically-Driven Therapeutic Agents Delivery System Using Iron Oxide Nanocages And Enhancement Of Exosome Secretion, A Potential Biological Drug Delivery Carrier, Min A Kang Sep 2023

Magnetically-Driven Therapeutic Agents Delivery System Using Iron Oxide Nanocages And Enhancement Of Exosome Secretion, A Potential Biological Drug Delivery Carrier, Min A Kang

Dissertations, Theses, and Capstone Projects

Nano-scale particles have attracted research attention due to their differences in properties such as penetration, circulation, and toxicity compared to bulk materials. This thesis mainly focused on using 20 nm iron oxide nanoparticles as siRNA delivery carriers under the alternating magnetic field and the development of a method to amplify the secretion of 150 nm exosomes from the cells, which could potentially use as a biological drug carrier.

Chapter 2 discusses a magnetically driven nanoparticle therapeutic agent delivery system, which efficiently modified the gene expression post-transcriptionally. In this work, we examined whether the caged-shaped 20nm iron oxide nanoparticles (IO-nanocages) can …


Characterization Of Pathological Tau Mutants, Charles J. Mcdonald Sep 2023

Characterization Of Pathological Tau Mutants, Charles J. Mcdonald

Dissertations, Theses, and Capstone Projects

Tau is a protein expressed exclusively in glia and neurons in the central nervous system and implicated in several neurogenerative diseases called “tauopathies”. Among all the tauopathies, one third is characterized by the presence of genetic mutations leading to the synthesis of tau proteins with single amino acid substitutions at specific locations and affecting protein function. While most of the initial studies have emphasize the functional role of tau as modulator of the axonal cytoskeleton, it has recently been well accepted that tau is also an intrinsically disordered protein that tends to form membraneless organelles called coacervates, due to a …


The Development Of Novel Radioimmunoconjugates For The Pet Imaging And Radioimmunotherapy Of Cancer, Samantha M. Sarrett Jun 2023

The Development Of Novel Radioimmunoconjugates For The Pet Imaging And Radioimmunotherapy Of Cancer, Samantha M. Sarrett

Dissertations, Theses, and Capstone Projects

Antibodies have long played a vital role in nuclear medicine for both the diagnosis and therapy of various malignancies. The role and development of antibodies in nuclear medicine can be broadly separated into three different categories: 1) bioconjugation strategies, 2) immunoPET imaging, and 3) radioimmunotherapy. This dissertation will attempt to comprehensively cover each of these categories through a series of studies, protocols, and reviews. For the bioconjugation strategies, we will describe the development of a novel site-selective bioconjugation strategy using an innovative lysine-targeting reagent, PFP-bisN3, to prepare [89Zr]Zr-SSKDFO-pertuzumab for visualizing HER2+ breast cancer. Further, …


Metabolic Reprogramming In Kras-Driven Cancer Cells, Ahmet Hatipoglu Jun 2023

Metabolic Reprogramming In Kras-Driven Cancer Cells, Ahmet Hatipoglu

Dissertations, Theses, and Capstone Projects

Cancer cells require nutrient uptake for anabolic reactions needed for cellular growth and proliferation. The mammalian target of rapamycin (mTOR) is a key regulator of cellular growth that links nutrient availability and growth factor signals. mTOR mediated signaling pathways are often dysregulated in a wide range of cancers. We previously reported that KRas-driven cancer cells sense exogenous lipids via de novo production of phosphatidic acid, which ultimately activates both mTOR complexes – mTORC1 and mTORC2. Activated mTORC2 phosphorylates the survival kinase Akt at Ser 473 which is required for full Akt activation. A direct substrate of Akt and a major …


Leveraging Bio-Inspired Molecules For Cancer Theranostics, Douglas S. Macpherson Feb 2023

Leveraging Bio-Inspired Molecules For Cancer Theranostics, Douglas S. Macpherson

Dissertations, Theses, and Capstone Projects

A variety of molecules can be radiolabeled and delivered to a cancer site for the purposes of diagnostics and therapy. Among the most promising of tumor targeting molecules are peptides and antibodies. These bio-inspired molecules can be designed and synthesized to target and respond to cancer cells based on the properties of those cells. Matrix metalloproteinase (MMP) enzymes are over-expressed by some metastatic cancers, in which they are responsible for the degradation and remodeling of the extracellular matrix. In recent years, MMPs have emerged as promising targets for enzyme-responsive diagnostic probes because oligopeptides can be designed to be selectively hydrolyzed …


Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster Oct 2022

Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster

Publications and Research

Metabolic reprogramming is now considered a hallmark of cancer cells. KRas-driven cancer cells use glutaminolysis to generate the tricarboxylic acid cycle intermediate α -ketoglutarate via a transamination reaction between glutamate and oxaloacetate. We reported previously that exogenously supplied unsaturated fatty acids could be used to synthesize phosphatidic acid–a lipid second messenger that activates both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTOR complex 2 (mTORC2). A key target of mTORC2 is Akt–a kinase that promotes survival and regulates cell metabolism. We report here that mono- unsaturated oleic acid stimulates the phosphoryla tion of ATP citrate lyase (ACLY) at …


Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie Sep 2022

Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie

Publications and Research

Background

Microbes are associated with many human diseases and influence drug efficacy. Small-molecule drugs may revolutionize biomedicine by fine-tuning the microbiota on the basis of individual patient microbiome signatures. However, emerging endeavors in small-molecule microbiome drug discovery continue to follow a conventional “one-drug-one-target-one-disease” process. A systematic pharmacology approach that would suppress multiple interacting pathogenic species in the microbiome, could offer an attractive alternative solution.

Results

We construct a disease-centric signed microbe–microbe interaction network using curated microbe metabolite information and their effects on host. We develop a Signed Random Walk with Restart algorithm for the accurate prediction of effect of microbes …


Role Of Nuclear Lamins In Oligodendrocyte Lineage Cells, Camila Yattah Sep 2022

Role Of Nuclear Lamins In Oligodendrocyte Lineage Cells, Camila Yattah

Dissertations, Theses, and Capstone Projects

Differentiation of oligodendrocytes from progenitor cells is a highly regulated process characterized by a series of molecular changes, resulting in nuclear and morphological features unique to the mature oligodendrocyte state. Heterochromatin formation starting at the nuclear periphery, as well as increased nuclear rigidity are characteristically observed. The nuclear periphery is characterized by the presence of the nuclear lamina and it has been implicated in higher-order genome organization in cells. Lamins are the protein components of the nuclear lamina, and their expression is dependent upon the cell differentiation stage of the cells. While Lamin B1 (LMNB1) expression is high in progenitors …


Novel Therapeutic Strategies For Alzheimer’S Disease: Prostaglandin D2 Signaling And Its Human Polymorphisms As Well As A Polypharmacological Approach, Charles H. Wallace Sep 2022

Novel Therapeutic Strategies For Alzheimer’S Disease: Prostaglandin D2 Signaling And Its Human Polymorphisms As Well As A Polypharmacological Approach, Charles H. Wallace

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is an age related neurodegenerative disease with pathology that includes amyloid plaques, neurofibrillary tangles and non-resolving neuroinflammation. Non-resolving neuroinflammation lasts the entire course of the disease and has deleterious effects and is often thought to accelerate AD pathology. Non-Steroidal Anti-inflammatory Drugs (NSAIDs) have commonly been used as therapeutics to treat pain, inflammation and vascular. NSAIDs work by altering the cyclooxygenase (COX) mediated biosynthesis of prostaglandins which are lipid mediators that have many physiological functions, for example nociception, inflammation and vasodilation. Epidemiological studies support the notion that NSAIDs could be used to treat AD. Yet, clinical trials using …


Prenatal Choline Supplementation During Maternal Obesity Alters Offspring Response To Western Diets, Hunter W. Korsmo Sep 2022

Prenatal Choline Supplementation During Maternal Obesity Alters Offspring Response To Western Diets, Hunter W. Korsmo

Dissertations, Theses, and Capstone Projects

Maternal obesity has led to an increase in adverse offspring developmental outcomes and a greater risk for long-term metabolic diseases. Choline, a semi-essential nutrient, can be incorporated into phosphatidylcholine (PC) as well as sphingomyelin (SM) and donate its labile methyl group for the remethylation of homocysteine after choline is oxidized to betaine. Prenatal choline insufficiency has been related to maternal obesity and metabolic diseases, such as metabolic associated fatty liver disease (MAFLD). Choline may interact with maternal obesity to influence the programming offspring.

Chapter 1 presents an introduction of choline and the various clinical outcomes associated with choline supplementation during …


Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor Sep 2022

Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor

Dissertations, Theses, and Capstone Projects

The tumor suppressor p53 (TP53) gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the oligomerization domain (OD) and C-terminal domain (CTD). The OD and CTD have been found to be critical for the tumor suppressor functionality of wild-type p53 (wtp53). Specific missense mutations in the DNA binding domain have been found to confer new gain-of-function (GOF) activities. Mutations that destabilize tetramer formation, or deletion of key lysine residues within the CTD, downregulate the ability of wtp53 to transactivate (increase the rate of transcription of) its target …


Novel Therapeutic Strategies For Alzheimer’S Disease: Targeting Toll-Like Receptor Signaling And A Multi-Target Approach, Giovanni Oliveros Sep 2022

Novel Therapeutic Strategies For Alzheimer’S Disease: Targeting Toll-Like Receptor Signaling And A Multi-Target Approach, Giovanni Oliveros

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is multifactorial, and its hallmarks include the formation of amyloid-beta (Ab) plaques and neurofibrillary tau tangles, accompanied by an increase in glial cell activation, culminating in neurodegeneration, chronic neuroinflammation, and cognitive decline in human patients. AD will cost the United States over $300 million this year alone and is projected to cost over $1 trillion by 2050, AD is a serious concern for the aging population, and efforts need to be redirected towards more effective therapeutic intervention strategies. Drugs aimed at halting AD progression have so far proven unsuccessful due to the development of pharmaceuticals that target …


Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn Jun 2022

Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn

Publications and Research

The paper describes guidelines for the planning, organization, and successful execution of virtual, global scientific conferences for global audiences. The guidelines are based on experience and lessons learned during the organization of the 3-day 2020 Virtual Systems Chemistry Symposium hosted on Zoom webinar and Twitter, held on May 2020 with over 1000 registered participants from 46 different countries.


Molecular Mechanism Of Rapamycin Resistance In Cancer Cells, Sohag Chakraborty Jun 2022

Molecular Mechanism Of Rapamycin Resistance In Cancer Cells, Sohag Chakraborty

Dissertations, Theses, and Capstone Projects

The mammalian target of rapamycin (mTOR) acts as the central regulator of multiple cellular processes including cell growth, proliferation, and survival by integrating signals via nutrients, growth factors, hormones, and energy sensing. In cancer cells, the mTOR pathway is highly dysregulated providing survival signals to the cells for their uncontrolled growth. Hence, mTOR has evolved to be a potential therapeutic target for cancer treatment for the past two decades. Application of micro-molar doses of Rapamycin in vitro has been found to successfully inhibit mTOR complex 1 (mTORC1) by blocking the phosphorylation of its downstream substrates- a) ribosomal protein p70 S6 …


Eukaryotic Initiation Factor 4e (Eif4e) In Complex With Eif4e Binding Protein 1 (4e-Bp1) Binds With Higher Affinity To M7gpppn Cap Of A Subset Of Human Mrnas, Izza F. Nawaz Apr 2022

Eukaryotic Initiation Factor 4e (Eif4e) In Complex With Eif4e Binding Protein 1 (4e-Bp1) Binds With Higher Affinity To M7gpppn Cap Of A Subset Of Human Mrnas, Izza F. Nawaz

Theses and Dissertations

Fluorescence anisotropy binding assays were used to analyze the binding of eIF4E in complex with 4E-BP1 onto the 5’ m7G cap of a subset of mRNA that are known to carry cap-independent translation. These studies suggest that 4E-BP1 increases eIF4E binding affinity to 5’cap of both FGF-9 and HIF-1𝝰.


Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss Apr 2022

Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss

Publications and Research

Viral mRNAs that lack a 5 m 7 GTP cap and a 3 poly-A tail rely on structural elements in their untranslated regions (UTRs) to form unique RNA-protein complexes that regulate viral translation. Recent studies of the barley yellow dwarf virus (BYDV) have revealed eukaryotic initiation factor 3 (eIF3) plays a significant role in facilitating communication be- tween its 5 and 3 UTRs by binding both UTRs simultaneously. This report uses in vitro translation assays, fluorescence anisotropy binding assays, and selective 2 -hydroxyl acylation analyzed by primer ex-tension (SHAPE) footprinting to identify secondary structures that are selectively interacting with eIF3. …


An In Silico Approach To Investigate The Structural And Biochemical Basis Of The Rna Binding Functions Of Nucleolin, Avdar San Feb 2022

An In Silico Approach To Investigate The Structural And Biochemical Basis Of The Rna Binding Functions Of Nucleolin, Avdar San

Dissertations, Theses, and Capstone Projects

Nucleolin (NCL) is a stress responsive multifunctional nucleolar protein and accounts for 10% of the total nucleolar protein content. NCL belongs to the class of RNA binding proteins (RBPs) that regulate many important cellular processes through their interactions with different RNA molecules. The dysregulation of RBPs and the RNA metabolism pathways they intersect is a known driver of tumorigenesis. NCL regulates ribosome biogenesis, chromatin remodeling, microRNA processing, and gene expression on multiple levels. The RNA-protein interactions of NCL are primarily driven by its four RNA binding domains (RBDs). NCL is known to interact with a growing list of primary-miRNA (pri-miRNA) …


Histone Post-Translational Modification Dysregulation Contributes To Toxicity In Amyotrophic Lateral Sclerosis Proteinopathy Models, Seth A. Bennett Feb 2022

Histone Post-Translational Modification Dysregulation Contributes To Toxicity In Amyotrophic Lateral Sclerosis Proteinopathy Models, Seth A. Bennett

Dissertations, Theses, and Capstone Projects

Amyotrophic Lateral Sclerosis (ALS) is the third most common adult onset neurodegenerative disorder worldwide. It is generally characterized by progressive paralysis starting at the limbs ultimately leading to death caused by respiratory failure. There is no cure and current treatments fail to slow the progression of the disease. As such, new treatment options are desperately needed. Epigenetic targets are an attractive possibility because they are reversible. Epigenetics refers to heritable changes in gene expression unrelated to changes in DNA sequence. Histone modifications, a main epigenetic mechanism, occur in many amino acid residues and include phosphorylation, acetylation, methylation as well as …


Role Of Metals In Human Immune System: Study Of Metal-Dependent Structural Changes Of S100a12 Protein, Aleksey Aleshintsev Feb 2022

Role Of Metals In Human Immune System: Study Of Metal-Dependent Structural Changes Of S100a12 Protein, Aleksey Aleshintsev

Dissertations, Theses, and Capstone Projects

S100A12 protein belongs to the S100 family of calcium-binding proteins and participates in the innate immune system. Antimicrobial proteins from the S100 family of the proteins (S100A12, S100A8/A9, etc.) are secreted and expressed by neutrophils during microbial infection and perform their antimicrobial activity through metal sequestration. While most S100 proteins function intracellularly, S100A12 is highly expressed and secreted into the extracellular space by neutrophils during infection. Sequestration of Zn2+ by S100A12 is aided by the nanomolar zinc binding affinity of the protein at neutral pH conditions, which is further enhanced upon calcium-binding. The Zn2+ binding scaffold in S100A12 …


Structural And Biochemical Investigations Of The Initiation Of Dna Replication In Bacteriophage Lambda And Escherichia Coli, Jillian D. Chase Feb 2022

Structural And Biochemical Investigations Of The Initiation Of Dna Replication In Bacteriophage Lambda And Escherichia Coli, Jillian D. Chase

Dissertations, Theses, and Capstone Projects

Faithful transmission of genetic information is requisite for the propagation of all life. DNA replication in each of the three domains of life requires the separation of double stranded DNA (dsDNA) into single stranded DNA (ssDNA) which then serves as a template for genomic duplication of each original DNA strand. Initiation of replication events occurs by tightly regulated processes during which specialized proteins are loaded at a specific locus within the genome, termed the origin of replication, in preparation of bidirectional replication events. A replicative helicase must be loaded or assembled on both strands of DNA at the origin to …


Paddling Along The Voltage Gated Sodium Channel Galaxy With Sea Anemone Toxins: Structural Studies Of The Interaction Between The Paddle Motif From Nav1.5div And Sea Anemone Toxin, Adel K. Hussein Feb 2022

Paddling Along The Voltage Gated Sodium Channel Galaxy With Sea Anemone Toxins: Structural Studies Of The Interaction Between The Paddle Motif From Nav1.5div And Sea Anemone Toxin, Adel K. Hussein

Dissertations, Theses, and Capstone Projects

Voltage gated sodium channels (VGSC) are membrane proteins that serve an important function in the central nervous system (CNS), peripheral nervous system (PNS), and cardiac muscles amongst others. The main function of VGSC is in the propagation of electrical signals by depolarizing excitable cells. Nine mammalian VGSC subtypes have been characterized, NaV1.1 – NaV1.9, that are expressed in a tissue specific manner, each with unique gating properties. Numerous diseases have been linked to defects in VGSC including epilepsy, mental retardation, long QT syndrome, and Brugada disease. Furthermore, these channels are one of the primary targets of …


Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn Jan 2022

Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn

Publications and Research

Mammalian cells, including cancer cells, are covered by a surface layer containing cell bound proteoglycans, glycoproteins, associated glycosaminoglycans and bound proteins that is commonly referred to as the glycocalyx. Solid tumors also have a dynamic fluid microenvironment with elevated interstitial flow. In the present work we further investigate the hypothesis that interstitial flow is sensed by the tumor glycocalyx leading to activation of cell motility and metastasis. Using a highly metastatic renal carcinoma cell line (SN12L1) and its low metastatic counterpart (SN12C) we demonstrate in vitro that the small molecule Suberoylanilide Hydroxamic Acid (SAHA) inhibits the heparan sulfate synthesis enzyme …


Principles Of General Chemistry, Jose Cobo Jan 2022

Principles Of General Chemistry, Jose Cobo

Open Educational Resources

No abstract provided.


High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig Dec 2021

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …


Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall Dec 2021

Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall

Publications and Research

Melanin is a major virulence factor in pathogenic fungi that enhances the ability of fungal cells to resist immune clearance. Cryptococcus neoformans is an important human pathogenic fungus that synthesizes melanin from exogenous tissue catecholamine precursors during infection, but the type of melanin made in cryptococcal meningoencephalitis is unknown. We analyzed the efficacy of various catecholamines found in brain tissue in supporting melanization using animal brain tissue and synthetic catecholamine mixtures reflecting brain tissue proportions. Solid-state NMR spectra of the melanin pigment produced from such mixtures yielded more melanin than expected if only the preferred constituent dopamine had been incorporated, …


Development And Validation Of A Method For The Determination Of Designer Benzodiazepines In Hair By Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Laura C. Defreitas Dec 2021

Development And Validation Of A Method For The Determination Of Designer Benzodiazepines In Hair By Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Laura C. Defreitas

Student Theses

In recent years, new designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogues of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop ways to accurately test for these compounds in different biological matrices. This study focused to develop and validate a method for determining 17 new designer benzodiazepines in hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). Hair samples were decontaminated, pulverized, and 20 mg of the sample was incubated in …