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Articles 6451 - 6480 of 13694

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Association Of Vitamin D Deficiency And Vdbp Gene Polymorphism With The Risk Of Ami In A Pakistani Population, Mujtaba Mubashir, Shaheena Anwar, Asal Khan Tareen, Naseema Mehboobali, Khalida Iqbal, Mohammad Iqbal Nov 2017

Association Of Vitamin D Deficiency And Vdbp Gene Polymorphism With The Risk Of Ami In A Pakistani Population, Mujtaba Mubashir, Shaheena Anwar, Asal Khan Tareen, Naseema Mehboobali, Khalida Iqbal, Mohammad Iqbal

Department of Biological & Biomedical Sciences

OBJECTIVE: To investigate the relationship of vitamin D deficiency and risk of AMI in a Pakistani population, and to find out any associationbetween vitamin D binding protein (VDBP) genotypes and risk of AMI in this population.
METHODS: In a comparative cross-sectional study, 246 patients (age: 20-70 years; 171 males and 75 females) with first AMI were enrolled with informed consent. Similarly, 345 healthy adults (230 males and 115 females) were enrolled as controls. Their fasting serum samples were analyzed for 25 (OH) vitamin D, lipids and other biomarkers using kit methods, while DNA was analyzed for VDBP genotypes using PCR-RFLP …


Mitochondrial Reactive Oxygen Species In Lipotoxic Hearts Induces Post-Translational Modifications Of Akap121, Drp1 And Opa1 That Promote Mitochondrial Fission, Kensuke Tsushima, Heiko Bugger, Adam R. Wende, Jamie Soto, Gregory A. Jenson, Austin R. Tor, Rose Mcglauflin, Helena C. Kenny, Yuan Zhang, Rhonda Souvenir, Xiao X. Hu, Crystal L. Sloan, Renata O. Pereira, Vitor A. Lira, Kenneth W. Spitzer, Terry L. Sharp, Kooresh I. Shoghi, Genevieve C. Sparagna, Eva A. Rog-Zielinska, Peter Kohl, Oleh Khalimonchuk, Jean E. Schaffer, E. Dale Abel Nov 2017

Mitochondrial Reactive Oxygen Species In Lipotoxic Hearts Induces Post-Translational Modifications Of Akap121, Drp1 And Opa1 That Promote Mitochondrial Fission, Kensuke Tsushima, Heiko Bugger, Adam R. Wende, Jamie Soto, Gregory A. Jenson, Austin R. Tor, Rose Mcglauflin, Helena C. Kenny, Yuan Zhang, Rhonda Souvenir, Xiao X. Hu, Crystal L. Sloan, Renata O. Pereira, Vitor A. Lira, Kenneth W. Spitzer, Terry L. Sharp, Kooresh I. Shoghi, Genevieve C. Sparagna, Eva A. Rog-Zielinska, Peter Kohl, Oleh Khalimonchuk, Jean E. Schaffer, E. Dale Abel

Department of Biochemistry: Faculty Publications

Rationale: Cardiac lipotoxicity, characterized by increased uptake, oxidation and accumulation of lipid intermediates, contributes to cardiac dysfunction in obesity and diabetes. However, mechanisms linking lipid overload and mitochondrial dysfunction are incompletely understood.

Objective: To elucidate the mechanisms for mitochondrial adaptations to lipid overload in postnatal hearts in vivo.

Methods and Results: Using a transgenic mouse model of cardiac lipotoxicity overexpressing long-chain acyl-CoA synthetase 1 in cardiomyocytes, we show that modestly increased myocardial fatty acid uptake leads to mitochondrial structural remodeling with significant reduction in minimum diameter. This is associated with increased palmitoyl-carnitine oxidation and increased reactive oxygen species (ROS) generation …


Association Of Vitamin D Binding Protein Polymorphism With Risk Of Type 2 Diabetes Mellitus In A Pakistani Urban Population: A Case Control Study, Khalida Iqbal, Najmul Islam, Iqbal Azam, Ali Asghar, Naseema Mehboobali, Mohammad Perwaiz Iqbal Nov 2017

Association Of Vitamin D Binding Protein Polymorphism With Risk Of Type 2 Diabetes Mellitus In A Pakistani Urban Population: A Case Control Study, Khalida Iqbal, Najmul Islam, Iqbal Azam, Ali Asghar, Naseema Mehboobali, Mohammad Perwaiz Iqbal

Department of Biological & Biomedical Sciences

Objective: To assess if genotypes/diplotypes of vitamin D binding protein have any association with type 2 diabetes mellitus.
Methods: This case-control study was conducted from January 2013 to July 2015 at the endocrinology clinics of the Aga Khan University Hospital, Karachi, and comprised adult patients with type 2 diabetes and their age- and gender-matched healthy controls. Venous blood was obtained and assessed for serum/plasma 25 hydroxyvitamin D, parathyroid hormone, calcium, alkaline phosphatase and creatinine. Deoxyribonucleic acid was isolated and genotyping was done by polymerase chain reaction-restriction fragment length polymorphismprocedures.
Results: Of the 330 participants, there were 165(50%) …


Effectiveness Of Composting As A Biosecure Disposal Method For Porcine Epidemic Diarrhea Virus (Pedv)-Infected Pig Carcasses, Sarah Vitosh-Sillman, John Dustin Loy, Bruce Brodersen, Clayton Kelling, Kent M. Eskridge, Amy Millmier Schmidt Nov 2017

Effectiveness Of Composting As A Biosecure Disposal Method For Porcine Epidemic Diarrhea Virus (Pedv)-Infected Pig Carcasses, Sarah Vitosh-Sillman, John Dustin Loy, Bruce Brodersen, Clayton Kelling, Kent M. Eskridge, Amy Millmier Schmidt

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine epidemic diarrhea virus (PEDV) is an enteric disease of swine that has emerged as a worldwide threat to swine herd health and production. Substantial research has been conducted to assess viability of the virus on surfaces of vehicles and equipment, in feed and water, and on production building surfaces, but little is known about the persistence in PEDV-infected carcasses and effective disposal methods thereof. This study was conducted to quantify the persistence of PEDV RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at various time-temperature combinations and in infected piglet carcasses subjected to composting. Although this method …


High-Throughput Single-Molecule Telomere Characterization, Jennifer Mccaffrey, Eleanor Young, Katy Lassahn, Justin Sibert, Steven Pastor, Harold Riethman, Ming Xiao Nov 2017

High-Throughput Single-Molecule Telomere Characterization, Jennifer Mccaffrey, Eleanor Young, Katy Lassahn, Justin Sibert, Steven Pastor, Harold Riethman, Ming Xiao

School of Medical Diagnostics & Translational Sciences Publications

We have developed a novel method that enables global subtelomere and haplotype-resolved analysis of telomere lengths at the single-molecule level. An in vitro CRISPR/Cas9 RNA-directed nickase system directs the specific labeling of human (TTAGGG) n DNA tracts in genomes that have also been barcoded using a separate nickase enzyme that recognizes a 7bp motif genome-wide. High-throughput imaging and analysis of large DNA single molecules from genomes labeled in this fashion using a nanochannel array system permits mapping through subtelomere repeat element (SRE) regions to unique chromosomal DNA while simultaneously measuring the (TTAGGG) n tract length at the end of each …


Using Competition Assays To Quantitatively Model Cooperative Binding By Transcription Factors And Other Ligands., Jacob Peacock, James B Jaynes Nov 2017

Using Competition Assays To Quantitatively Model Cooperative Binding By Transcription Factors And Other Ligands., Jacob Peacock, James B Jaynes

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: The affinities of DNA binding proteins for target sites can be used to model the regulation of gene expression. These proteins can bind to DNA cooperatively, strongly impacting their affinity and specificity. However, current methods for measuring cooperativity do not provide the means to accurately predict binding behavior over a wide range of concentrations.

METHODS: We use standard computational and mathematical methods, and develop novel methods as described in Results.

RESULTS: We explore some complexities of cooperative binding, and develop an improved method for relating in vitro measurements to in vivo function, based on ternary complex formation. We derive …


Thermodynamic And Kinetic Aspects Of Hen Egg White Lysozyme Amyloid Assembly, Tatiana Miti Nov 2017

Thermodynamic And Kinetic Aspects Of Hen Egg White Lysozyme Amyloid Assembly, Tatiana Miti

USF Tampa Graduate Theses and Dissertations

Deposition of protein fibers with a characteristic cross-β sheet structure is the molecular marker associated with human disorders ranging from Alzheimer's disease to type II diabetes and spongiform encephalopathy. Given the large number of non-disease related proteins and peptides that have been shown to form amyloid fibrils in vitro, it has been suggested that amyloid fibril formation represents a generic protein phase transition. In the last two decades it has become clear that the same protein/peptide can assemble into distinct morphologically and structurally amyloid aggregates depending on the solution conditions. Moreover, recent studies have shown that the early stage, oligomeric …


Redox-Active Nanomaterials For Nanomedicine Applications, C. M. Sims, S. K. Hanna, D. A. Heller, C. P. Horoszko, M. E. Johnson, A. R. Montoro Bustos, V. Reipa, Kathryn R. Riley, B. C. Nelson Oct 2017

Redox-Active Nanomaterials For Nanomedicine Applications, C. M. Sims, S. K. Hanna, D. A. Heller, C. P. Horoszko, M. E. Johnson, A. R. Montoro Bustos, V. Reipa, Kathryn R. Riley, B. C. Nelson

Chemistry & Biochemistry Faculty Works

Nanomedicine utilizes the remarkable properties of nanomaterials for the diagnosis, treatment, and prevention of disease. Many of these nanomaterials have been shown to have robust antioxidative properties, potentially functioning as strong scavengers of reactive oxygen species. Conversely, several nanomaterials have also been shown to promote the generation of reactive oxygen species, which may precipitate the onset of oxidative stress, a state that is thought to contribute to the development of a variety of adverse conditions. As such, the impacts of nanomaterials on biological entities are often associated with and influenced by their specific redox properties. In this review, we overview …


Synthesis, Crystal Structure, And Photoluminescent Properties Of 3,3′,4,4′-Tetraethyl-5,5′-Divinyl-2,2′-Bipyrrole Derivatives, Toru Okawara, Reo Kawano, Hiroya Morita, Alan Finkelstein, Renjiro Toyofuku, Kanako Matsumoto, Kenji Takehara, Toshihiko Nagamura, Seiji Iwasa, Sanjai Kumar Oct 2017

Synthesis, Crystal Structure, And Photoluminescent Properties Of 3,3′,4,4′-Tetraethyl-5,5′-Divinyl-2,2′-Bipyrrole Derivatives, Toru Okawara, Reo Kawano, Hiroya Morita, Alan Finkelstein, Renjiro Toyofuku, Kanako Matsumoto, Kenji Takehara, Toshihiko Nagamura, Seiji Iwasa, Sanjai Kumar

Publications and Research

Photoluminescent divinylbipyrroles were synthesized from 3,3′,4,4′-tetraetyl-2,2′-bipyrrole-5,5′-dicarboxaldehyde and activated methylene compounds via aldol condensation.For mechanistic clarity, molecular structures of Meldrum’s acid- and 1,3-dimethylbarbituricacid-derived divinylbipyrroles were determined by single-crystal X-ray diffraction. Photoluminescentproperties of the synthesized divinylbipyrroles in dichloromethane were found to be dependent onthe presence of electron withdrawing groups at the vinylic terminal. The divinylbipyrroles derivedfrom malononitrile, Meldrum’s acid, and 1,3-dimethylbarbituric acid showed fluorescent peaks at553, 576, and 602 nm respectively. Computational studies indicated that the alkyl substituents on thebipyrrole 3 and 3′positions increased energy level of the highest occupied molecular orbital (HOMO)compared to the unsubstituted derivatives and provided rationale for the …


Organelle-Specific Single-Molecule Imaging Of Α4Β2 Nicotinic Receptors Reveals The Effect Of Nicotine On Receptor Assembly And Cell-Surface Trafficking, Ashley M. Fox-Lee, Faruk H. Moonschi, Christopher I. Richards Oct 2017

Organelle-Specific Single-Molecule Imaging Of Α4Β2 Nicotinic Receptors Reveals The Effect Of Nicotine On Receptor Assembly And Cell-Surface Trafficking, Ashley M. Fox-Lee, Faruk H. Moonschi, Christopher I. Richards

Chemistry Faculty Publications

Nicotinic acetylcholine receptors (nAChRs) assemble in the endoplasmic reticulum (ER) and traffic to the cell surface as pentamers composed of α and β subunits. Many nAChR subtypes can assemble with varying subunit ratios, giving rise to multiple stoichiometries exhibiting different subcellular localization and functional properties. In addition to the endogenous neurotransmitter acetylcholine, nicotine also binds and activates nAChRs and influences their trafficking and expression on the cell surface. Currently, no available technique can specifically elucidate the stoichiometry of nAChRs in the ER versus those in the plasma membrane. Here, we report a method involving single-molecule fluorescence measurements to determine the …


What’S In A Name?, Michael D. Schaller, Gary Mcdowell, André Porter, Dorothy Shippen, Katherine L. Friedman, Matthew S. Gentry, Tricia R. Serio, Wesley I. Sundquist Oct 2017

What’S In A Name?, Michael D. Schaller, Gary Mcdowell, André Porter, Dorothy Shippen, Katherine L. Friedman, Matthew S. Gentry, Tricia R. Serio, Wesley I. Sundquist

Molecular and Cellular Biochemistry Faculty Publications

Numerous concerns have been raised about the sustainability of the biomedical research enterprise in the United States. Improving the postdoctoral training experience is seen as a priority in addressing these concerns, but even identifying who the postdocs are is made difficult by the multitude of different job titles they can carry. Here, we summarize the detrimental effects that current employment structures have on training, compensation and benefits for postdocs, and argue that academic research institutions should standardize the categorization and treatment of postdocs. We also present brief case studies of two institutions that have addressed these challenges and can provide …


An Organismal Model For Gene Regulatory Networks In The Gut-Associated Immune Response, Katherine M. Buckley, J P. Rast Oct 2017

An Organismal Model For Gene Regulatory Networks In The Gut-Associated Immune Response, Katherine M. Buckley, J P. Rast

Biochemistry and Molecular Medicine Faculty Publications

The gut epithelium is an ancient site of complex communication between the animal immune system and the microbial world. While elements of self-non-self receptors and effector mechanisms differ greatly among animal phyla, some aspects of recognition, regulation, and response are broadly conserved. A gene regulatory network (GRN) approach provides a means to investigate the nature of this conservation and divergence even as more peripheral functional details remain incompletely understood. The sea urchin embryo is an unparalleled experimental model for detangling the GRNs that govern embryonic development. By applying this theoretical framework to the free swimming, feeding larval stage of the …


Kinetic Characterization Of Listeria Monocytogenes 2-C- Methyl-D-Erythritol 4-Phosphate Cytidylyltransferase ( Cms ) Enzymes Using High Performance Liquid Chromatography ( Hplc ), Mark Oblazny Oct 2017

Kinetic Characterization Of Listeria Monocytogenes 2-C- Methyl-D-Erythritol 4-Phosphate Cytidylyltransferase ( Cms ) Enzymes Using High Performance Liquid Chromatography ( Hplc ), Mark Oblazny

Theses and Dissertations

Infectious diseases, with increasing prevalence of antibiotic resistant bacteria, coupled with the declining rate in discovery of antimicrobial agents, impose one of the most significant threats to human health. Here we identify 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase (CMS) as a valid target for antibiotic development which is an enzyme in pathogenic organisms that leads to the biosynthesis of isoprene precursor molecules. Isoprene molecules are one of nature’s most common building blocks that are vital to many biological metabolic processes and are synthesized via the mevalonic acid dependent (MVA), or methylerythritol phosphate (MEP) pathway. Vertebrates utilize the MVA pathway, while many pathogenic bacteria …


The Biochemical Assessment Of Two Secreted Acid Phosphatases From Leishmania Tarentolae, Their Response To Electric Fields, Glycosidase Incubation, And / Or Vanadium, Benjamin M. Dorsey Oct 2017

The Biochemical Assessment Of Two Secreted Acid Phosphatases From Leishmania Tarentolae, Their Response To Electric Fields, Glycosidase Incubation, And / Or Vanadium, Benjamin M. Dorsey

Theses and Dissertations

Leishmaniasis, as defined by the Center for Disease Control and Prevention, is a neglected tropical disease with 1.6 million new cases reported each year. However, there is yet to be safe, effective, and affordable treatments provided to those affected by this disease1. Still underappreciated as a potential pharmaceutical targets, especially for cutaneous leishmaniasis infections, are the two isozymes of secreted acid phosphatase (SAP); secreted acid phosphatase 1 (SAP1) and secreted acid phosphatase 2 (SAP2). These enzymes are involved in the survival of the parasite in the sand fly vector, and the prevention of host macrophages from forming parasitophorous vacuole and …


Cell Division Regulation In Staphylococcus Aureus, Catherine M. Spanoudis Oct 2017

Cell Division Regulation In Staphylococcus Aureus, Catherine M. Spanoudis

USF Tampa Graduate Theses and Dissertations

Cell division is a fundamental biological process that occurs in all kingdoms of life. Our understanding of cell division in bacteria stems from studies in the rod-shaped model organisms: Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. The molecular underpinnings of cell division regulation in non-rod-shaped bacteria remain to be studied in detail. Rod-shaped bacteria possess many positive and negative regulatory proteins that are essential to the proper placement of the division septa and ultimately the production of two identical daughter cells, many of which are absent in cocci. Given that essential cell division proteins are attractive antibacterial drug targets, it …


Registration And Grouping Algorithms In Protein Nmr Derived Peak Lists And Their Application In Protein Nmr Reference Correction, Andrey Smelter, Xi Chen, Eric C. Rouchka, Hunter N. B. Moseley Oct 2017

Registration And Grouping Algorithms In Protein Nmr Derived Peak Lists And Their Application In Protein Nmr Reference Correction, Andrey Smelter, Xi Chen, Eric C. Rouchka, Hunter N. B. Moseley

Commonwealth Computational Summit

Nuclear magnetic resonance spectroscopy of proteins (protein NMR) is a powerful analytical technique for studying structure and dynamics of proteins. Almost all aspects of protein NMR have been accelerated by the development of software tools that enable the analysis of NMR spectral data and its utilization in studying protein structure and dynamics. This includes software for raw NMR processing, spectral visualization, protein resonance assignment, and structure determination. However, full automation of protein NMR data analysis is still a work in progress and data analysis still requires an expert NMR spectroscopist utilizing an array of software tools.

While manual resonance assignment …


Aberrant Coordination Geometries Discovered In Most Abundant Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley Oct 2017

Aberrant Coordination Geometries Discovered In Most Abundant Metalloproteins, Sen Yao, Robert M. Flight, Eric C. Rouchka, Hunter N. B. Moseley

Commonwealth Computational Summit

Metalloproteins play crucial biochemical roles in our body and are essential across all domains of life. The structural environment around a metal ion, especially the coordination geometry (CG), is both sequentially and functionally relevant. Studies of the metalloprotein’s CG will greatly help alleviate the imbalance between the ample sequence data available and the insufficient knowledge on protein functions. Current methodologies in characterizing metalloproteins’ CG consider only previously reported CG (canonical CG) models based primarily on nonbiological chemical context. Exceptions to these canonical CG models can greatly hamper the ability to characterize metalloproteins both structurally and functionally.


Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie Oct 2017

Nanoparticle Delivery Of Mir-34a Eradicates Long-Term-Cultured Breast Cancer Stem Cells Via Targeting C22orf28 Directly, Xiaoti Lin, Weiyu Chen, Fengqin Wei, Binhua P. Zhou, Mien-Chie Hung, Xiaoming Xie

Molecular and Cellular Biochemistry Faculty Publications

Rationale: Cancer stem cells (CSCs) have been implicated as the seeds of therapeutic resistance and metastasis, due to their unique abilities of self-renew, wide differentiation potentials and resistance to most conventional therapies. It is a proactive strategy for cancer therapy to eradicate CSCs. Methods: Tumor tissue-derived breast CSCs (BCSC), including XM322 and XM607, were isolated by fluorescence-activated cell sorting (FACS); while cell line-derived BCSC, including MDA-MB-231.SC and MCF-7.SC, were purified by magnetic-activated cell sorting (MACS). Analyses of microRNA and mRNA expression array profiles were performed in multiple breast cell lines. The mentioned nanoparticles were constructed following the standard molecular cloning …


Prebiotic Rna Network Formation: A Taxonomy Of Molecular Cooperation, Cole Mathis, Sanjay N. Ramprasad, Sara Imari Walker, Niles Lehman Oct 2017

Prebiotic Rna Network Formation: A Taxonomy Of Molecular Cooperation, Cole Mathis, Sanjay N. Ramprasad, Sara Imari Walker, Niles Lehman

Chemistry Faculty Publications and Presentations

Cooperation is essential for evolution of biological complexity. Recent work has shown game theoretic arguments, commonly used to model biological cooperation, can also illuminate the dynamics of chemical systems. Here we investigate the types of cooperation possible in a real RNA system based on the Azoarcusribozyme, by constructing a taxonomy of possible cooperative groups. We construct a computational model of this system to investigate the features of the real system promoting cooperation. We find triplet interactions among genotypes are intrinsically biased towards cooperation due to the particular distribution of catalytic rate constants measured empirically in the real system. For other …


The Molecular Mechanism Of N-Acetylglucosamine Side-Chain Attachment To The Lancefield Group A Carbohydrate In Streptococcus Pyogenes, Jeffrey Rush, Rebecca J. Edgar, Pan Deng, Jing Chen, Haining Zhu, Nina M. Van Sorge, Andrew J. Morris, Konstantin V. Korotkov, Natalia Korotkova Oct 2017

The Molecular Mechanism Of N-Acetylglucosamine Side-Chain Attachment To The Lancefield Group A Carbohydrate In Streptococcus Pyogenes, Jeffrey Rush, Rebecca J. Edgar, Pan Deng, Jing Chen, Haining Zhu, Nina M. Van Sorge, Andrew J. Morris, Konstantin V. Korotkov, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

In many Lactobacillales species (i.e. lactic acid bacteria), peptidoglycan is decorated by polyrhamnose polysaccharides that are critical for cell envelope integrity and cell shape and also represent key antigenic determinants. Despite the biological importance of these polysaccharides, their biosynthetic pathways have received limited attention. The important human pathogen, Streptococcus pyogenes, synthesizes a key antigenic surface polymer, the Lancefield group A carbohydrate (GAC). GAC is covalently attached to peptidoglycan and consists of a polyrhamnose polymer, with N-acetylglucosamine (GlcNAc) side chains, which is an essential virulence determinant. The molecular details of the mechanism of polyrhamnose modification with GlcNAc are …


The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, Lindsey Wagner, Caleb L. Adams Oct 2017

The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, Lindsey Wagner, Caleb L. Adams

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Functional Characteristics And Genomic Sequencing Of Antarctic Environmental Isolates, Amanda Kemper, Christina Aigner, Michelle Tigges, Sara Anderson Oct 2017

Functional Characteristics And Genomic Sequencing Of Antarctic Environmental Isolates, Amanda Kemper, Christina Aigner, Michelle Tigges, Sara Anderson

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Ligand Modulation Of Sidechain Dynamics In A Wild-Type Human Gpcr, Lindsay D. Clark, Igor Dikiy, Karen Chapman, Karin Ej Rodstrom, James Aramini, Michael V. Levine, George Khelashvili, Soren Gf Rasmussen, Kevin H. Gardner, Daniel M. Rosenbaum Oct 2017

Ligand Modulation Of Sidechain Dynamics In A Wild-Type Human Gpcr, Lindsay D. Clark, Igor Dikiy, Karen Chapman, Karin Ej Rodstrom, James Aramini, Michael V. Levine, George Khelashvili, Soren Gf Rasmussen, Kevin H. Gardner, Daniel M. Rosenbaum

Publications and Research

GPCRs regulate all aspects of human physiology, and biophysical studies have deepened our understanding of GPCR conformational regulation by different ligands. Yet there is no experimental evidence for how sidechain dynamics control allosteric transitions between GPCR conformations. To address this deficit, we generated samples of a wild-type GPCR (A2AR) that are deuterated apart from 1H/13C NMR probes at isoleucine d1 methyl groups, which facilitated 1H/13C methyl TROSY NMR measurements with opposing ligands. Our data indicate that low [Na+] is required to allow large agonist-induced structural changes in A2AR, and that patterns of sidechain dynamics substantially differ between agonist (NECA) and …


Microfluidic Biopsy Trapping Device For The Real-Time Monitoring Of The Tumor Microenvironment, Angela Holton Oct 2017

Microfluidic Biopsy Trapping Device For The Real-Time Monitoring Of The Tumor Microenvironment, Angela Holton

USF Tampa Graduate Theses and Dissertations

The tumor microenvironment is composed of cellular and stromal components such as tumor cells, mesenchymal cells, immune cells, cancer associated fibroblasts and the supporting extracellular matrix. The tumor microenvironment provides crucial support for growth and progression of tumor cells and affects tumor response to therapeutic interventions. To better understand tumor biology and to develop effective cancer therapeutic agents it is important to develop preclinical platforms that can faithfully recapitulate the tumor microenvironment and the complex interaction between the tumor and its surrounding stromal elements. Drug studies performed in vitro with conventional two-dimensional cancer cell line models do not optimally represent …


2-D Electrophoresis Modeling Of Multienzyme Cutting Of Polypeptides, Howard Mayes Oct 2017

2-D Electrophoresis Modeling Of Multienzyme Cutting Of Polypeptides, Howard Mayes

Theses

2-Dimensional Electrophoresis is one of the tools in the identification of proteins by molecular weight and pH. The display of molecular weight allows the researcher to quickly identify whether a specific protein or peptide string is in the sample. The pH measurement allows even better resolution between different species in the sample. The MultiEnzyme ElectroPhoresis (MEEP) program tries to model that by providing a graph that displays separated protein strings by both molecular weight and pH. The ability to cleave the protein with 43 different enzyme variations allows the researcher to analyze appropriate enzymes to isolate a protein subsequence before …


First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai Oct 2017

First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai

Chemistry & Biochemistry Faculty Works

All-optical spin switching is a potential trailblazer for information storage and communication at an unprecedented fast rate free of magnetic fields. However, the current wisdom is largely based on semiempirical models of effective magnetic fields and heat pulses, so it is difficult to provide high-speed design protocols for actual devices. Here, we carry out a massively parallel first-principles and model calculation for 13 spin systems and magnetic layers, free of any effective field, to establish a simpler and alternative paradigm of laser-induced ultrafast spin reversal and to point out a path to a full-integrated photospintronic device. It is the interplay …


The Efficiency Of Dna Repair Processes In Proximity Of G 4 Dna Structures, Gloria Alvarado Oct 2017

The Efficiency Of Dna Repair Processes In Proximity Of G 4 Dna Structures, Gloria Alvarado

Theses and Dissertations

Guanine-rich segments of genomes promote the formation of a four-stranded DNA structure called G-quadruplex (G4 DNA). While evolutionarily conserved, guanine repeats show increased rates of mutagenesis and instability, and this is likely associated with G4 formation. In this thesis, I sought to clarify the molecular sources of genetic instability by testing the repair, excision, and synthesis through guanine-rich DNA. Using E. coli UDG and human SMUG1, I found that uracil is inefficiently repaired in proximity to G4 DNA in vitro. Investigation of E. coli exonuclease III and exonuclease I activity indicated that G4 DNA is a block to activity and …


Phylogenetic Evidence From Freshwater Crayfishes That Cave Adaptation Is Not An Evolutionary Dead-End., David B Stern, Jesse Breinholt, Carlos Pedraza-Lara, Marilú López-Mejía, Christopher L Owen, Heather Bracken-Grissom, James W Fetzner, Keith A Crandall Oct 2017

Phylogenetic Evidence From Freshwater Crayfishes That Cave Adaptation Is Not An Evolutionary Dead-End., David B Stern, Jesse Breinholt, Carlos Pedraza-Lara, Marilú López-Mejía, Christopher L Owen, Heather Bracken-Grissom, James W Fetzner, Keith A Crandall

Computational Biology Institute

Caves are perceived as isolated, extreme habitats with a uniquely specialized biota, which long ago led to the idea that caves are "evolutionary dead-ends." This implies that cave-adapted taxa may be doomed for extinction before they can diversify or transition to a more stable state. However, this hypothesis has not been explicitly tested in a phylogenetic framework with multiple independently evolved cave-dwelling groups. Here, we use the freshwater crayfish, a group with dozens of cave-dwelling species in multiple lineages, as a system to test this hypothesis. We consider historical patterns of lineage diversification and habitat transition as well as current …


1H, 15N, And 13C Chemical Shift Assignments Of The Regulatory Domain Of Human Calcineurin, Dinesh K. Yadav, Sri Ramya Tata, John Hunt, Erik C. Cook, Trevor P. Creamer, Nicholas C. Fitzkee Oct 2017

1H, 15N, And 13C Chemical Shift Assignments Of The Regulatory Domain Of Human Calcineurin, Dinesh K. Yadav, Sri Ramya Tata, John Hunt, Erik C. Cook, Trevor P. Creamer, Nicholas C. Fitzkee

Center for Structural Biology Faculty Publications

Calcineurin (CaN) plays an important role in T-cell activation, cardiac system development and nervous system function. Previous studies have demonstrated that the regulatory domain (RD) of CaN binds calmodulin (CaM) towards the N-terminal end. Calcium-loaded CaM activates the serine/threonine phosphatase activity of CaN by binding to the RD, although the mechanistic details of this interaction remain unclear. It is thought that CaM binding at the RD displaces the auto-inhibitory domain (AID) from the active site of CaN, activating phosphatase activity. In the absence of calcium-loaded CaM, the RD is disordered, and binding of CaM induces folding in the RD. In …


Activation Of The Phospholipid Scramblase Tmem16f By Nanosecond Pulsed Electric Field (Nspef) Facilitates Its Diverse Cytophysiological Effects, Claudia Muratori, Andrei G. Pakhomov, Elena Gianulis, Jade Meads, Maura Casciola, Peter A. Mollica, Olga N. Pakhomova Oct 2017

Activation Of The Phospholipid Scramblase Tmem16f By Nanosecond Pulsed Electric Field (Nspef) Facilitates Its Diverse Cytophysiological Effects, Claudia Muratori, Andrei G. Pakhomov, Elena Gianulis, Jade Meads, Maura Casciola, Peter A. Mollica, Olga N. Pakhomova

Bioelectrics Publications

Nanosecond pulsed electric fields (nsPEF) are emerging as a novel modality for cell stimulation and tissue ablation. However, the downstream protein effectors responsible for nsPEF bioeffects remain to be established. Here we demonstrate that nsPEF activate TMEM16F (or Anoctamin 6), a protein functioning as a Ca2+-dependent phospholipid scramblase and Ca2+-activated chloride channel. Using confocal microscopy and patch clamp recordings, we investigated the relevance of TMEM16F activation for several bioeffects triggered by nsPEF, including phosphatidylserine (PS) externalization, nanopore-conducted currents, membrane blebbing, and cell death. In HEK 293 cells treated with a single 300-ns pulse of 25.5 kV/cm, …