Chemistry Commons^™

Mutational Analysis Of The Nitrogenase Carbon Monoxide Protective Protein Cown Reveals That A Conserved C‑Terminal Glutamic Acid Residue Is Necessary For Its Activity, Dustin L. Willard, Joshuah J. Arellano, Mitch Underdahl, Terrence M. Lee, Avinash S. Ramaswamy, Gabriella Fumes, Agatha Kliman, Emily Y. Wong, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nitrogenase is the only enzyme that catalyzes the reduction of nitrogen gas into ammonia. Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Many nitrogen fixing bacteria protect nitrogenase from CO inhibition using the protective protein CowN. This work demonstrates that a conserved glutamic acid residue near the C-terminus of Gluconacetobacter diazotrophicus CowN is necessary for its function. Mutation of the glutamic acid residue abolishes both CowN’s protection against CO inhibition and the ability of CowN to bind to nitrogenase. In contrast, a conserved C-terminal cysteine residue is not important for CO protection by CowN. Overall, this work …

Beyond N-Dopants For Organic Semiconductors: Use Of Bibenzo[D]Imidazoles In Uv-Promoted Dehalogenation Reactions Of Organic Halides, Kan Tang, Megan R. Brown, Chad Risko, Melissa K. Gish, Garry Rumbles, Phuc H. Pham, Oana R. Luca, Stephen Barlow, Seth R. Marder

UK CARES Faculty Publications

2,2’-Bis(4-dimethylaminophenyl)- and 2,2'-dicyclohexyl-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[d]imidazole ((N-DMBI)2 and (Cyc-DMBI)2) are quite strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced bond-cleavage reactions, specifically dehalogenations. The dimers reduce halides that have reduction potentials less cathodic than ca. −2 V vs ferrocenium/ferrocene, especially under UV photoexcitation (using a 365 nm LED). In the case of benzyl halides, the products are bibenzyl derivatives, whereas aryl halides are reduced to the corresponding arenes. The potentials of the halides that can be …

Expflow: A Graphical User Interface For Automated Reproducible Electrochemistry, Rebekah Duke, Siamak Mahmoudi, Aman Preet Kaur, Vinayak Bhat, Ian C. Dingle, Nathan C. Stumme, Scott K. Shaw, David L. Eaton, Asmund Vego, Chad Risko

UK CARES Faculty Publications

Reproducible data and results underpin the credibility and integrity of research findings across the sciences. However, experiments and measurements conducted across laboratories, or by different researchers, are often hindered by incomplete or inaccessible procedural data. Additionally, the time and resources needed to manually perform repeat experiments and analyses limit the scale at which experiments can be reproduced. Both improved methods for recording and sharing experimental procedures in machine- readable formats and efforts towards automation can be beneficial to circumvent these issues. Here we report the development of ExpFlow, a data collection, sharing, and reporting software currently customized for electrochemical experiments. …

Deficiency Of Acute-Phase Serum Amyloid A Exacerbates Sepsis-Induced Mortality And Lung Injury In Mice, Ailing Ji, Andrea C. Trumbauer, Victoria P. Noffsinger, Luke W. Meredith, Brittany Dong, Qian Wang, Ling Guo, Xiangan Li, Frederick C. De Beer, Nancy R. Webb, Lisa R. Tannock, Marlene E. Starr, Christopher M. Waters, Preetha Shridas

Saha Cardiovascular Research Center Faculty Publications

Serum amyloid A (SAA) is a family of proteins, the plasma levels of which may increase >1000-fold in acute inflammatory states. We investigated the role of SAA in sepsis using mice deficient in all three acute-phase SAA isoforms (SAA-TKO). SAA deficiency significantly increased mortality rates in the three experimental sepsis mouse models: cecal ligation and puncture (CLP), cecal slurry (CS) injection, and lipopolysaccharide (LPS) treatments. SAA-TKO mice had exacerbated lung pathology compared to wild-type (WT) mice after CLP. A bulk RNA sequencing performed on lung tissues excised 24 h after CLP indicated significant enrichment in the expression of genes associated …

Development Of A Methodology For The Quantification Of Reaerosolization Of A Biological Contaminate Surrogate Particle From A Military Uniform Fabric, George Cooksey, Jeremy M. Slagley, Casey W. Cooper, Douglas Lewis, Alisha Helm

Faculty Publications

In a mass casualty medical evacuation after a bioaerosol (BA) dispersal event, a decontamination (DC) method is needed that can both decontaminate and prevent biological particle (BP) re-aerosolization (RA) of contaminated clothes. However, neither the efficacy of current DC methods nor the risk of BP RA is greatly explored in the existing literature. The goals of this study were to develop a repeatable method to quantify the RA of a biological contaminant off military uniform fabric swatches and to test the efficacy of one DC protocol (high-volume, low-pressure water) using 1 µm polystyrene latex (PSL) spheres as a surrogate. A …

Impacts Of Hydrophobic Mismatch On Antimicrobial Peptide Efficacy And Bilayer Permeabilization., Steven Meier, Zachary M Ridgway, Angela L Picciano, Gregory A. Caputo

College of Science & Mathematics Departmental Research

Antimicrobial resistance continues to be a major threat to world health, with the continued emergence of resistant bacterial strains. Antimicrobial peptides have emerged as an attractive option for the development of novel antimicrobial compounds in part due to their ubiquity in nature and the general lack of resistance development to this class of molecules. In this work, we analyzed the antimicrobial peptide C18G and several truncated forms for efficacy and the underlying mechanistic effects of the sequence truncation. The peptides were screened for antimicrobial efficacy against several standard laboratory strains, and further analyzed using fluorescence spectroscopy to evaluate binding to …

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Development Of Antibacterial Neural Stimulation Electrodes Via Hierarchical Surface Restructuring And Atomic Layer Deposition., Henna Khosla, Wesley Seche, Daniel Ammerman, Sahar Elyahoodayan, Gregory A. Caputo, Jeffrey Hettinger, Shahram Amini, Gang Feng

College of Science & Mathematics Departmental Research

Miniaturization and electrochemical performance enhancement of electrodes and microelectrode arrays in emerging long-term implantable neural stimulation devices improves specificity, functionality, and performance of these devices. However, surgical site and post-implantation infections are amongst the most devastating complications after surgical procedures and implantations. Additionally, with the increased use of antibiotics, the threat of antibiotic resistance is significant and is increasingly being recognized as a global problem. Therefore, the need for alternative strategies to eliminate post-implantation infections and reduce antibiotic use has led to the development of medical devices with antibacterial properties. In this work, we report on the development of electrochemically …

Dynamic Regulation Of Store-Operated Calcium Entry By Protein S-Acylation, Goutham Kodakandla

Theses and Dissertations

Calcium plays a pivotal role in many physiological functions in cells. Cytosolic calcium levels are finely tuned by calcium ion channels, pumps, and intracellular organelles. Store-operated calcium entry (SOCE) is when depletion of endoplasmic reticulum (ER) calcium stores activates a calcium sensor known as stromal interaction molecule 1 (STIM1). Activation of STIM1 leads to a conformational change from a compact state to an extended state. This extended state of STIM1 allows it to bind to a calcium channel in the plasma membrane (PM) known as Orai1. The binding of Orai1 and STIM1 leads to opening of Orai1 channels and calcium …

Impact Of Common Face Mask Regeneration Processes On The Structure, Morphology And Aerosol Filtration Efficiency Of Porous Flat Sheet Polysulfone Membranes Fabricated Via Nonsolvent-Induced Phase Separation (Nips), Ebuka A. Ogbuoji, Anastasia Myers, Amber Haycraft, Isabel Escobar

UK CARES Faculty Publications

The potential of flat sheet polymeric membranes as a sustainable solution for reusable facemask filters was investigated by analyzing the effect of common face mask regeneration processes on polysulfone (PSf) membranes’ structure, morphology, and aerosol filtration efficiency. The impact of regeneration processes, such as isopropanol (IPA), detergent and bleach washes, and ultraviolet light exposure, was for the first time compared between surgical masks, N95 masks and flat sheet PSf membranes. The PSf membranes were fabricated via non- solvent induced phase separation (NIPS), and demonstrated a higher particulate filtration efficiency (99.06 ± 1.38%) for PM0.3 i.e., particulate matter of 0.3 μm …

Chain Conformation And Exciton Delocalization In A Push-Pull Conjugated Polymer, Yulong Zheng, Rahul Venkatesh, Connor P. Callaway, Campbell Viersen, Kehinde H. Fagbohungbe, Aaron L. Liu, Chad Risko, Elsa Reichmanis, Carlos Silva-AcuñA

UK CARES Faculty Publications

Linear and nonlinear optical line shapes reveal details of excitonic structure in polymer semiconductors. We implement absorption, photoluminescence, and transient absorption spectroscopies in DPP-DTT, an electron push−pull copolymer, to explore the relationship between their spectral line shapes and chain conformation, deduced from resonance Raman spectroscopy and from ab initio calculations. The viscosity of precursor polymer solutions before film casting displays a transition that suggests gel formation above a critical concentration. Upon crossing this viscosity deflection concentration, the line shape analysis of the absorption spectra within a photophysical aggregate model reveals a gradual increase in interchain excitonic coupling. We also observe …

Development Of Poly(Acrylamide)-Based Hydrogel Composites With Powdered Activated Carbon For Controlled Sorption Of Pfoa And Pfos In Aqueous Systems, Maria Victoria X. Klaus, Angela M. Gutierrez, J. Zach Hilt

UK CARES Faculty Publications

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic compounds developed for various applications; some are connected to adverse health impacts including immunosuppression and higher susceptibility to some cancers. Current PFAS remediation treatments from aqueous sources include granular activated carbon (GAC) adsorption, membrane separation, and anion- exchange resin (AER) removal. Each has specific disadvantages, hence the need for a new and efficient technology. Herein, acrylamide-based hydrogel composites were synthesized with powdered activated carbon (PAC) and characterized to determine their affinity for PFAS. Physicochemical characterization included Fourier-Transform infrared spectroscopy (FTIR) to identify chemical composition, thermogravimetric analysis (TGA) to confirm PAC loading percentage, and …

Photocurable Ionized Vinylimidazole Liquid Salt For Antibacterial Application, Gina Park, Lisa Ahlberg, Robert Zdor

Celebration of Research and Creative Scholarship

There has been an increasing demand for antibacterial dental composite as it can prevent the biofilm formation and the adhesion of bacteria after the treatment causing the consequential cavities. Previous study explored the antibacterial activity of the heterogenous mixture of heterocyclic polymer and resin. It showed limitations as the mixture did not show antibacterial activity since the mixture could only contain a small amount of heterocyclic polymer within the resin due to its inconvenience of shaping and low miscibility. To overcome this limitation, this research focused on synthesizing heterocyclic antibacterial monomer liquid salt and curing it with UV light to …

Determining The Ideal Concentrations Of Ethanol And Propylene Glycol In Ethosomes For Transdermal Delivery Of Vitamin D3, Rebecca Conner

Harrisburg University Research Symposium: Highlighting Research, Innovation, & Creativity

Vitamin D₃ is an important chemical in the human body, however, many Americans have low levels of this vitamin. There are plenty of oral supplementations for Vitamin D₃ deficiency, but those of older age and busy schedules may struggle to meet the minimum requirement. A recently developed ethosomal transmembrane delivery system (Touitou, 2000), similar to liposomes but also containing ethanol, allows users to apply a gel dermally and have the desired drug or active ingredient reach the bloodstream faster. However, there is considerable variation in the concentration of ethanol and permeation enhancers used. Using an affordable method to …

Multiexciton Quintet State Populations In A Rigid Pyrene-Bridged Parallel Tetracene Dimer, Liang-Chun Lin, Tanner Smith, Qianxiang Ai, Brandon K. Rugg, Chad Risko, John E. Anthony, Niels H. Damrauer, Justin C. Johnson

UK CARES Faculty Publications

The multiexciton quintet state, 5 TT, generated as a singlet fission intermediate in pairs of molecular chromophores, is a promising candidate as a qubit or qudit in future quantum information science schemes. In this work, we synthesize a pyrene-bridged parallel tetracene dimer, TPT, with an optimized interchromophore coupling strength to prevent the dissociation of 5 TT to two decorrelated triplet (T1) states, which would contaminate the spin-state mixture. Long-lived and strongly spin-polarized pure 5 TT state population is observed via transient absorption spectroscopy and transient/pulsed electron paramagnetic resonance spectroscopy, and its lifetime is estimated to be >35 ms, with the …

Raman Spectral Cytopathology For Cancer Diagnostic Applications, Fiona Lyng, Damian Traynor, Isha Behl, Declan O'Dea, Hugh Byrne

Books/Book Chapters

Histopathology is currently regarded as the “gold standard” patient sampling technique for cancer diagnostics. It involves extraction of a tissue sample, or biopsy, which is then sectioned and stained for evaluation by a pathologist [1]. Cytopathology, on the other hand, is the field of disease diagnosis at the cellular level [2], necessitating only the microscopic evaluation of samples of cells which can be harvested by less invasive methods such as exfoliative brushing, needle probes or from biofluids. Based on the identification of abnormalities in cellular appearance, cytopathology is currently widely used to aid in the screening of cancer, as well …

Structural Insights Into The Cl-Par-4 Protein: Ionic Requirements, Conformational Transitions, And Interaction With Cisplatin, Krishna Kumar Raut

Chemistry & Biochemistry Theses & Dissertations

Cancer continues to be the leading global cause of death, with challenges in early diagnosis, drug resistance, non-specific drug targeting, and cancer recurrence and metastasis posing formidable obstacles in cancer therapy. In this context, Prostate Apoptosis Response-4 (Par-4), a pro-apoptotic tumor suppressor protein, emerged as a promising therapeutic target due to its ability to selectively induce apoptosis in cancer cells, thereby minimizing the drug-associated adverse effects. However, a comprehensive understanding of the structural features of Par-4, specifically the caspase-cleaved fragment (cl-Par-4), is crucial for therapeutic advancements.

This dissertation investigated the effects of various ions, both monovalent and divalent, on the …

Comparative Study Of Guanidine-, Acetamidine- And Urea-Based Chloroaluminate Electrolytes For An Aluminum Battery, Iwan Sumarlan, Anand Kunverji, Anthony J Lucio, A Robert Hillman, Karl S Ryder

Faculty, Staff and Student Publications

Aluminum-based batteries are a promising alternative to lithium-ion as they are considered to be low-cost and more friendly to the environment. In addition, aluminum is abundant and evenly distributed across the globe. Many studies and Al battery prototypes use imidazolium chloroaluminate electrolytes because of their good rheological and electrochemical performance. However, these electrolytes are very expensive, and so cost is a barrier to industrial scale-up. A urea-based electrolyte, AlCl3:Urea, has been proposed as an alternative, but its performance is relatively poor because of its high viscosity and low conductivity. This type of electrolyte has become known as an ionic liquid …

Microplastics In Water, Their Effects On The Aquatic Ecosystem And Human Public Health, And The Proposed Solutions, Mohanad Abouserie

The Undergraduate Research Journal

We could be swallowing a credit card's weight in plastic every week. Microplastic water pollution is becoming a threat to both humans and aquatic creatures. In this research, microplastic water contamination is discussed, and divergent solutions are proposed. This paper attempts to investigate the causes and effects of such pollution and analyze the current solutions for this issue. The adopted research method is secondary research, where several studies are explored and analyzed. This study explains numerous causes for this issue like cosmetics, cleaning products, factories, and sewage. Consequently, this contamination can negatively impact the organs and metabolisms of the living …

Equine In Vivo Metabolite Profiling Of The Selective Androgen Receptor Modulator Lgd-3303 For Doping Control, Malin Nilsson Broberg, Heather Knych, Ulf Bondesson, Curt Pettersson, Börje Tidstedt, Scott Stanley, Mario Thevis, Mikael Hedeland

UK CARES Faculty Publications

LGD-3303 is a Selective Androgen Receptor Modulator (SARM) that is prohibited in both equine and human sports due to its anabolic properties. The aim of this study was to investigate the equine in vivo metabolite profile of LGD-3303 and identify drug metabolites that can be suitable as new and improved analytical targets for equine doping control. This was performed by an oral administration of 0.05 mg⋅kg 1 LGD-3303 to horses, where blood and urine samples were collected up to 96 h after administration. The in vivo samples consisting of plasma, urine and hydrolyzed urine were analyzed utilizing ultra-high performance liquid …

Bacteroides Fragilis In The Gut Microbiomes Of Alzheimer’S Disease Activates Microglia And Triggers Pathogenesis In Neuronal C/Ebpβ Transgenic Mice, Yiyuan Xia, Yifan Xiao, Zi-Hao Wang, Ashfaqul M. Alam, John P. Haran, Beth A. Mccormick, Xiji Shu, Xiaochuan Wang, Keqiang Ye

Markey Cancer Center Faculty Publications

Gut dysbiosis contributes to Alzheimer’s disease (AD) pathogenesis, and Bacteroides strains are selectively elevated in AD gut microbiota. However, it remains unknown which Bacteroides species and how their metabolites trigger AD pathologies. Here we show that Bacteroides fragilis and their metabolites 12-hydroxy-heptadecatrienoic acid (12-HHTrE) and Prostaglandin E2 (PGE2) activate microglia and induce AD pathogenesis in neuronal C/EBPβ transgenic mice. Recolonization of antibiotics cocktail-pretreated Thy1-C/EBPβ transgenic mice with AD patient fecal samples elicits AD pathologies, associated with C/EBPβ/Asparaginyl endopeptidase (AEP) pathway upregulation, microglia activation, and cognitive disorders compared to mice receiving healthy donors’ fecal microbiota transplantation (FMT). Microbial 16S rRNA sequencing …

Syne1 Mutation Is Associated With Increased Tumor Mutation Burden And Immune Cell Infiltration In Ovarian Cancer, Laura M. Harbin, Nan Lin, Frederick R. Ueland, Jill M. Kolesar

Markey Cancer Center Faculty Publications

SYNE1, a nuclear envelope protein critical for cellular structure and signaling, is downregulated in numerous malignancies. SYNE1 alterations are found in 10% of gynecologic malignancies and 5% of epithelial ovarian cancers. Previous studies demonstrated an association between SYNE1 mutation, increased tumor mutation burden (TMB), and immunotherapy response. This study evaluates the SYNE1 mutation frequency, association with TMB, and downstream effects of SYNE1 mutation in ovarian cancer. Genetic information, including whole-exome sequencing, RNA analysis, and somatic tumor testing, was obtained for consenting ovarian cancer patients at an academic medical center. Mutation frequencies were compared between the institutional cohort and The Cancer …

Unleashing The Potential Of 1,3-Diketone Analogues As Selective Lh2 Inhibitors, Juhoon Lee, Hou-Fu Guo, Shike Wang, Yazdan Maghsoud, Erik Antonio Vázquez-Montelongo, Zhifeng Jing, Rae M. Sammons, Eun Jeong Cho, Pengyu Ren, G. Andrés Cisneros, Jonathan M. Kurie, Kevin N. Dalby

Markey Cancer Center Faculty Publications

Lysyl hydroxylase 2 (LH2) catalyzes the formation of highly stable hydroxylysine aldehyde-derived collagen cross-links (HLCCs), thus promoting lung cancer metastasis through its capacity to modulate specific types of collagen cross-links within the tumor stroma. Using 1 and 2 from our previous high-throughput screening (HTS) as lead probes, we prepared a series of 1,3-diketone analogues, 1−18, and identified 12 and 13 that inhibit LH2 with IC50’s of approximately 300 and 500 nM, respectively. Compounds 12 and 13 demonstrate selectivity for LH2 over LH1 and LH3. Quantum mechanics/molecular mechanics (QM/MM) modeling indicates that the selectivity of 12 and 13 may stem from …

Computational And Experimental Investigation Of Elemental Sulfur And Polysulfide, Jyoti Sharma

Dissertations

Petroleum processing results in the generation of significant quantities of elemental sulfur (S₈), leading to a surplus of sulfur worldwide. Despite its abundance and low cost, the use of sulfur in value-added organic compound synthesis is limited due to its unpredictable and misunderstood reactivity. This dissertation aims to address this issue by tackling it from two angles. Firstly, by utilizing Density Functional Theory (DFT) calculations, the reactivity of sulfur in the presence of nucleophiles is studied. This facilitates the identification of organic polysulfide intermediates that can be generated under different conditions, as well as the corresponding reactivity for …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Additive Effects Of Cyclic Peptide [R4w4] When Added Alongside Azithromycin And Rifampicin Against Mycobacterium Avium Infection, Melissa Kelley, Kayvan Sasaninia, Arbi Abnousian, Ali Badaoui, James Owens, Abrianna Beever, Nala Kachour, Rakesh Kumar Tiwari, Vishwanath Venketaraman

Pharmacy Faculty Articles and Research

Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) …

Quercetin As An Anticancer Candidate For Glioblastoma Multiforme By Targeting Akt1, Mmp9, Abcb1, And Vegfa: An In Silico Study, Muhammad Hermawan Widyananda, Setyaki Kevin Pratama, Arif Nur Muhammad Ansori, Yulanda Antonius, Viol Dhea Kharisma, Ahmad Affan Ali Murtadlo, Vikash Jakhmola, Maksim Rebezov, Mars Khayrullin, Marina Derkho, Emdad Ullah, Raden Joko Kuncoroningrat Susilo, Suhailah Hayaza, Alexander Patera Nugraha, Annise Proboningrat, Amaq Fadholly, Mada Triandala Sibero, Rahadian Zainul

Karbala International Journal of Modern Science

Quercetin, a natural compound present in various fruits and vegetables, shows promise as a potential inhibitor for glioblastoma multiforme (GBM) development. This study aims to examine the anti-GBM potential of Quercetin. The protein target of Quercetin is identified and analyzed using databases such as NCBI, SEA, CTD, and STRING. Protein-protein interaction (PPI) and functional annotation are carried out based on the obtained target proteins. Molecular docking and dynamics simulations are employed using AutoDock Vina and WebGro tools to analyze the interaction between Quercetin and its target proteins. The prediction of protein targets reveals that Quercetin directly targets four proteins associated …

Investigating The Impact On Private Water Supply Of Hydraulic Fracturing Communication With An Abandoned Conventional Gas Well In New Freeport, Pa, Kiley Miller

Electronic Theses and Dissertations

In June of 2022 a “frac out” occurred in New Freeport, PA when an unconventional gas well under development by hydraulic fracturing, communicated with an abandoned gas well to the surface. An initial “zone of impact” encompassed much of the town’s main thoroughfare. Water samples were obtained from 17 private water wells, 5 springs and 1 pond (31 total samples) and analyzed for cations, anions, and light hydrocarbons. Methane was found in 18 of the samples, both located within and outside of the “zone of impact”. Mass ratio analyses indicated contamination from both unconventional and conventional wells. Interferometric Synthetic Aperture …

Probing Conformational Landscapes Of Binding And Allostery In The Sars-Cov-2 Omicron Variant Complexes Using Microsecond Atomistic Simulations And Perturbation-Based Profiling Approaches: Hidden Role Of Omicron Mutations As Modulators Of Allosteric Signaling And Epistatic Relationships, Gennady M. Verkhivker, Mohammed Alshahrani, Grace Gupta, Sian Xiao, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this study, we systematically examine the conformational dynamics, binding and allosteric communications in the Omicron BA.1, BA.2, BA.3 and BA.4/BA.5 spike protein complexes with the ACE2 host receptor using molecular dynamics simulations and perturbation-based network profiling approaches. Microsecond atomistic simulations provided a detailed characterization of the conformational landscapes and revealed the increased thermodynamic stabilization of the BA.2 variant which can be contrasted with the BA.4/BA.5 variants inducing a significant mobility of the complexes. Using the dynamics-based mutational scanning of spike residues, we identified structural stability and binding affinity hotspots in the Omicron complexes. Perturbation response scanning and network-based mutational …

Activation Of The Renin–Angiotensin–Aldosterone System Is Attenuated In Hypertensive Compared With Normotensive Pregnancy, Robin C. Shoemaker, Marko Poglitsch, Hong Huang, Katherine Vignes, Aarthi Srinivasan, Cynthia Cockerham-Morris, Aric Schadler, John Anthony Bauer, John O'Brien

UK CARES Faculty Publications

Hypertension during pregnancy increases the risk of adverse maternal and fetal outcomes, but the mechanisms of pregnancy hypertension are not precisely understood. Elevated plasma renin activity and aldosterone concentrations play an important role in the normal physiologic adaptation to pregnancy. These effectors are reduced in patients with pregnancy hypertension, creating an opportunity to define the features of the renin–angiotensin–aldosterone system (RAAS) that are characteristic of this disorder. In the current study, we used a novel LC-MS/MS-based methodology to develop comprehensive profiles of RAAS peptides and effectors over gestation in a cohort of 74 pregnant women followed prospectively for the development …