Physical Sciences and Mathematics Commons^™

Women In Stem Conference, Maryann Rettig, Sara E. Hubbard Ph.D

Arkansas Women in STEM Conference

Analysis of BPA Leaching from Feminine Hygiene Products into Simulated Vaginal Fluid using Fluorescence Spectrophotometry

Maryann Rettig and Sara E. Hubbard, Ph.D.

Bisphenol-A (BPA) is a chemical compound commonly used to produce several plastics and epoxy resins. Recently, BPA has also been detected in feminine hygiene products. Because of a structural resemblance to estradiol, BPA can act as an endocrine disruptor, which has linked BPA to several health complications such as cancer development, reduced fertility, and early puberty. In recent summer research at Ouachita Baptist University, it was determined that fluorescence spectrophotometry could be used to monitor BPA leaching over …

Computer Aided Design Of Aromatic Foldamer Targeting Protein-Protein Interaction, Bamidele Towolawi

Graduate Student and Postdoctoral Fellow Symposium

With the computational tools developed in our lab for accurate prediction of structures and solution dynamics of aromatic foldamers, we now target protein-protein interaction (PPI) by appending proteinogenic side chains on the external surfaces of the helical aromatic foldamers. Particularly, the activation of a regulatory protein NF-κB, a key player in the inflammatory response and cell proliferation, involves binding of NEMO (NF-κB Essential Modulator) with linear di-ubiquitin. In this study, we designed various sequences based on established protocols and investigated, by utilizing molecular dynamics (MD) simulations, their potential binding to di-ubiquitin, specifically targeting the NEMO binding interface. This study complements …

Methionyl-Trna Synthetase Synthetic And Proofreading Activities Are Determinants Of Antibiotic Persistence, Whitney N. Wood, Miguel Angel Rubio, Lorenzo Eugenio Leiva, Gregory J. Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial antibiotic persistence is a phenomenon where bacteria are exposed to an antibiotic and the majority of the population dies while a small subset enters a low metabolic, persistent, state and are able to survive. Once the antibiotic is removed the persistent population can resuscitate and continue growing. Several different molecular mechanisms and pathways have been implicated in this phenomenon. A common mechanism that may underly bacterial antibiotic persistence is perturbations in protein synthesis. To investigate this mechanism, we characterized four distinct metG mutants for their ability to increase antibiotic persistence. Two metG mutants encode changes near the catalytic site …

Nitrene-Transfer Chemistry To C-H And C═C Bonds Mediated By Triangular Coinage Metal Platforms Supported By Triply Bridging Pnictogen Elements Sb(Iii) And Bi(Iii), Meenakshi Sharma, Reece M. Fritz, Joseph O. Adebanjo, Zhou Lu, Thomas R. Cundari, Mohammad A. Omary, Amitava Choudhury, Pericles Stavropoulos

Chemistry Faculty Research & Creative Works

Tripodal Ligands (TMG3trphen-E) That Feature Heavy Pnictogen Elements (E = Sb(III), Bi(III)) And Tetramethylguanidinyl (TMG) Arms Have Been Explored In Stabilizing Cu(I) And Ag(I) Sites And Facilitating Nitrene-Transfer Chemistry. Compounds [(TMG3trphen-E)M3(Μ-X)3] (M = Cu(I), Ag(I); X = Cl, Br, I) Have Been Generated Upon Extraction Of M3(Μ-X)3 Units From MX Sources, Exhibiting Support Of The Crown-Shaped M3(Μ-X)3 Fragment By M-NTMG Bonds And Triply Bridging E → M3 Interactions. Orbital Interactions Between Cu(I) Sites And NTMG Residues Are More Dominant Than Sb/Bi → Cu3 Donor Interactions Between The Sb 5s Or Bi 6s Orbitals And Admixed Cu 4s/3d Orbitals, With Larger …

In Silico Analysis Of C-Type Lectins As Co-Infection Receptors Of Dengue And Chikungunya Viruses In Aedes Aegypti, Munawir Sazali, R. C. Hidayat Soesilohadi, Nastiti Wijayanti, Tri Wibawa, Arif Nur Muhammad Ansori

Makara Journal of Science

Aedes aegypti is a primer vector of dengue virus (DENV) and chikungunya virus (CHIKV). The susceptibility of mosquitoes to DENV and CHIKV depends on their recognition receptor of pathogens. C-type lectins (CTLs) are an important mediator of virus infection in A. aegypti. This study aims to identify potential receptors and determine the binding affinity between ligand–receptor interaction, CTLs and virus envelopes (DENV-1, 2, 3, and 4 and CHIKV) interaction based on in silico analysis. Sample sequences were obtained from GenBank (NCBI), and 10 CTLs were acquired from VectorBase. Homology modeling based on a minimum standard of 20% was processed …

Synergistic Effect Of Acylpyrazolone Integrated With Multiwalled Carbon Nanotubes On The Electrochemical Analysis Of Ascorbic Acid, Emi Norzehan Mohamad Mahbob, Mohamad Syahrizal Ahmad, Illyas Md Isa, Norhayati Hashim, Anwar Ul-Hamid, Mohamad Idris Saidin, Suyanta Suyanta, Sofian Ibrahim

Makara Journal of Science

Square wave voltammetry, cyclic voltammetry, chronocoulometry, and electrochemical impedance spectroscopy were employed to assess ascorbic acid’s electrochemical behavior in multiwalled carbon nanotubes (MWCNTs)/carbon paste electrode (CPE) modified by 1-phenyl-3-methyl-4-metafluorobenzoyl-5-pyrazolone (HPMmFBP). The ascorbic acid’s irreversible oxidation peak appeared at approximately 0.5 V. The shifting of the peak potential at the pH range of 6.0–8.4 showed the involvement of protons in the ascorbic acid oxidation. Moreover, the shifting of the peak potential with scan rate in the range of 0.07–0.4 V/s confirmed that the oxidation reaction was irreversible. Under optimized conditions, the oxidative peak current showed linear dependence on the ascorbic acid’s …

Size Limits And Fission Channels Of Doubly Charged Noble Gas Clusters, Ianessa Stromberg, Stefan Bergmeister, Lisa Ganner, Fabio Zappa, Paul Scheier, Olof Echt, Elisabeth Gruber

Faculty Publications

Small, highly charged liquid droplets are unstable with respect to spontaneous charge separation when their size drops below the Rayleigh limit or, in other words, their fissility parameter X exceeds the value 1. The absence of small doubly charged atomic cluster ions in mass spectra below an element-specific appearance size n_a has sometimes been attributed to the onset of barrierless fission at X = 1. However, more realistic models suggest that n_a marks the size below which the rate of fission surpasses that of competing dissociative channels, and the Rayleigh limit of doubly charged van der Waals clusters …

Efficient Removal Of Chemical Organic Demand And Total Organic Carbon From Leachate Using Heterogeneous Fenton Catalyst Based On Activated Carbon, Amar Idir, Mounir Ziati, Mohamed Bouzid

Emirates Journal for Engineering Research

Organic components contained in leachates resulting from decomposition of waste are difficult to degrade. Leachate volume and its composition vary depending on biogeochemistry of site type of deposited residues, and the age of sanitary landfill. The present study aims to develop efficient heterogeneous Fenton oxidation of organic matter, expressed in terms of chemical organic demand (COD) and total organic carbon (TOC) of leachate using the newly synthesized iron-modified activated carbon. The characterization of catalyst revealed that the Fe(II) was successfully introduced onto the original activated carbon (AC) and diversified the material’s surface morphology and elemental compounds. The heterogeneous Fenton oxidation …

New Ways To Improve Dispersibility Of Nanotubes: Approaching From The Formation Of Silicon Nanoparticles By High Energy Reactive Ball Milling (Herbm) In Polar Solvents, Julie P. Vanegas, Yolanda V. Gutierrez, Joaquin Rivera, Juan García Jr.

Research Symposium

Background: This research aims to synthesize stable silicon nanoparticles using different molar ratios of N-Cyclohexyl-2-pyrrolidone (CHP) and Silicon to demonstrate if there is any significance towards the production of effective nanotubes. To determine this, the synthesized nanoparticles will be characterized by scanning electron microscopy (SEM), UV visible absorption spectroscopy, and photoluminescence spectroscopy (PL).

Methods: 50 Mg of silicon wafer are added with differing ratios of ligand (CHP), 5mL of water, and 3 steel iron balls into a ball milling vial. Vials are then placed into a ball milling apparatus for 7 cycles or 3.5 hours. Once the cycles are complete, …

Mechanistic Investigation Of C—C Bond Activation Of Phosphaalkynes With Pt(0) Complexes, Roberto M. Escobar, Abdurrahman C. Ateşin, Christian Müller, William D. Jones, Tülay Ateşin

Research Symposium

Carbon–carbon (C–C) bond activation has gained increased attention as a direct method for the synthesis of pharmaceuticals. Due to the thermodynamic stability and kinetic inaccessibility of the C–C bonds, however, activation of C–C bonds by homogeneous transition-metal catalysts under mild homogeneous conditions is still a challenge. Most of the systems in which the activation occurs either have aromatization or relief of ring strain as the primary driving force. The activation of unstrained C–C bonds of phosphaalkynes does not have this advantage. This study employs Density Functional Theory (DFT) calculations to elucidate Pt(0)-mediated C–CP bond activation mechanisms in phosphaalkynes. Investigating the …

Embedding Information Literacy Practices In An Upper Division Chemistry Lab Class At A University In The United States Of America, Christopher Randles, Matilynn Lamm, Katy A. Miller

Faculty Scholarship and Creative Works

This poster discusses the implementation of information literacy into an upper division inorganic chemistry lab and the strategies employed to develop students’ information literacy in the laboratory course.

Doubly Charged Dimers And Trimers Of Heavy Noble Gases, Gabriel Schöpfer, Stefan Bergmeister, Milan Ončák, Ianessa Stromberg, Masoomeh Mahmoodi-Darian, Paul Scheier, Olof Echt, Elisabeth Gruber

Faculty Publications

Many doubly charged heteronuclear dimers are metastable or even thermodynamically stable with respect to charge separation. Homonuclear dicationic dimers, however, are more difficult to form. He₂²⁺ was the first noble gas dimer predicted to be metastable and, decades later, observed. Ne₂²⁺ is the only other dicationic noble gas dimer that has been detected so far. Here, we present a novel approach to form fragile dicationic species, by post-ionization of singly charged ions that are embedded in helium nanodroplets (HNDs). Bare ions are then extracted by colliding the HNDs with helium gas. We detect homonuclear doubly charged …

A Multi-Omics Investigation Into The Mechanism Of Action Of An Anti-Tubercular Fatty Acid Analog, Isin T. Sakallioglu, Amith S. Maroli, Aline De Lima Leite, Darrell D. Marshall, Boone W. Evans, Denise K. Zinniel, Patrick H. Dussault, Raul G. Barletta, Robert Powers

Patrick Dussault Publications

The mechanism of action (MoA) of a clickable fatty acid analogue 8-(2-Cyclobuten-1-yl)octanoic acid (DA-CB) has been investigated for the first time. Proteomics, metabolomics, and lipidomics were combined with a network analysis to investigate the MoA of DA-CB against Mycobacterium smegmatis (Msm). The metabolomics results showed that DA-CB has a general MoA related to that of ethionamide, a mycolic acid inhibitor that targets enoyl-ACP reductase (InhA), but DA-CB likely inhibits a step downstream from InhA. Our combined multi-omics approach showed that DA-CB appears to disrupt the pathway leading to the biosynthesis of mycolic acids, an essential mycobacterial fatty acid …

Leveraging The Hmbc To Facilitate Metabolite Identification, Fatema Bhinderwala, Thao Vu, Thomas G. Smith, Julian Kosacki, Darrell D. Marshall, Yuhang Xu, Martha D. Morton, Robert Powers

Chemistry Department: Faculty Publications

The accuracy and ease of metabolite assignments from a complex mixture are expected to be facilitated by employing a multi-spectral approach. The 2D ¹H-¹³C HSQC and 2D ¹H-¹H-TOCSY are the experiments commonly used for metabolite assignments. The 2D ¹H-¹³C HSQC-TOCSY and 2D ¹H-¹³C HMBC are routinely used by natural products chemists but have seen minimal usage in metabolomics despite the unique information, the nearly complete ¹H-¹H and ¹H-¹³C and spin systems provided by these experiments that may improve the accuracy and reliability …

Role Of Electronegativity In Environmentally Persistent Free Radicals (Epfrs) Formation On Zno, Syed Monjur Ahmed, Reuben Oumnov, Orhan Kizilkaya, Randall W. Hall, Philip T. Sprunger, Robert L. Cook

Natural Sciences and Mathematics | Faculty Scholarship

Environmentally persistent free radicals (EPFRs), a group of emerging pollutants, have significantly longer lifetimes than typical free radicals. EPFRs form by the adsorption of organic precursors on a transition metal oxide (TMO) surface involving electron charge transfer between the organic and TMO. In this paper, dihalogenated benzenes were incorporated to study the role of electronegativity in the electron transfer process to obtain a fundamental knowledge of EPFR formation mechanism on ZnO. Upon chemisorption on ZnO nanoparticles at 250 °C, electron paramagnetic resonance (EPR) confirms the formation of oxygen adjacent carbon-centered organic free radicals with concentrations between 1016 and 1017 spins/g. …

Β-Sheets Mediate The Conformational Change And Allosteric Signal Transmission Between The Aslov2 Termini, Sian Xiao, Mayar Terek Ibrahim, Gennady M. Verkhivker, Brian D. Zoltowski, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

Avena sativa phototropin 1 light-oxygen-voltage 2 domain (AsLOV2) is a model protein of Per-Arnt-Sim (PAS) superfamily, characterized by conformational changes in response to external environmental stimuli. This conformational change begins with the unfolding of the N-terminal A'α helix in the dark state followed by the unfolding of the C-terminal Jα helix. The light state is characterized by the unfolded termini and the subsequent modifications in hydrogen bond patterns. In this photoreceptor, β-sheets are identified as crucial components for mediating allosteric signal transmission between the two termini. Through combined experimental and computational investigations, the Hβ …

Novel Inhibitors To Mmpl3 Transporter Of Mycobacterium Tuberculosis By Structure-Based High-Throughput Virtual Screening And Molecular Dynamics Simulations, Hetanshi Choksi, Justin Carbone, Nicholas J. Paradis, Lucas Bennett, Candice Bui-Linh, Chun Wu

College of Science & Mathematics Departmental Research

Tuberculosis (TB)-causing bacterium Mycobacterium tuberculosis (Mtb) utilizes mycolic acids for building the mycobacterial cell wall, which is critical in providing defense against external factors and resisting antibiotic action. MmpL3 is a secondary resistance nodulation division transporter that facilitates the coupled transport of mycolic acid precursor into the periplasm using the proton motive force, thus making it an attractive drug target for TB infection. In 2019, X-ray crystal structures of MmpL3 from M. smegmatis were solved with a promising inhibitor SQ109, which showed promise against drug-resistant TB in Phase II clinical trials. Still, there is a pressing need to discover more …

Investigating The Structural Ensemble And Dynamic Interactions Of Protein Interacting With C-Kinase 1 (Pick1) Using Computational Tools, Amy E. Stevens

Chemistry and Chemical Biology ETDs

Protein Interacting with C Kinase-1 (PICK1) is a scaffolding protein that offers a promising solution to support individuals suffering from substance use disorders. While many efforts have been put towards identifying small-molecule drugs with the potential to target PICK1 and ultimately support individuals suffering from the effects of substance use disorders, all efforts have so far fallen short. The purpose of this work is to use computational tools to assist the design of a small-molecule inhibitor of PICK1 while also advancing the knowledge of its biological functions. This work provides information that is currently missing the field by (1) revealing …

Highly Efficient Dopamine Sensing With A Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure, Harish Singh, Jiandong Wu, Kurt A.L. Lagemann, Manashi Nath

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon nanotube-encapsulated nickel selenide composite nanostructures were used as nonenzymatic electrochemical sensors for dopamine detection. These composite nanostructures were synthesized through a simple, one-step, and environmentally friendly chemical vapor deposition method, wherein the CNTs were formed in situ from pyrolysis of a carbon-rich metallo-organic precursor. The composition and morphology of these hybrid NiSe2-filled carbon nanostructures were confirmed by powder X-ray diffraction, Raman, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy images. Electrochemical tests demonstrated that the as-synthesized hybrid nanostructures exhibited outstanding electrocatalytic performance toward dopamine oxidation, with a high sensitivity of 19.62 μA μM-1 cm-2, low detection limit, broad linear …

Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan

Michigan Tech Publications, Part 2

Neuroinflammation and brain oxidative stress are recognized as significant contributors to hypertension including salt sensitive hypertension. Extracellular vesicles (EVs) play an essential role in intercellular communication in various situations, including physiological and pathological ones. Based on this evidence, we hypothesized that EVs derived from the brains of hypertensive rats with salt sensitivity could trigger neuroinflammation and oxidative stress during hypertension development. To test this hypothesis, we compared the impact of EVs isolated from the brains of hypertensive Dahl Salt-Sensitive rats (DSS) and normotensive Sprague Dawley (SD) rats on inflammatory factors and mitochondrial reactive oxygen species (mtROS) production in primary neuronal …

Assessment Of Mucin 13 (Muc13) As An Imaging Target For Guiding Colorectal Cancer Treatment: A Pathway Towards Theranostic Development, Ryan P. Coll, Aiko Yamaguchi, Jianbo Wang, Xiaoxia Wen, Denise Hernandez, Subhash C. Chauhan, H. Charles Manning

Research Symposium

Background: A theranostic strategy combining diagnostic imaging and targeted therapy in a single regimen is proposed for improved management and treatment of colorectal cancer (CRC). Increased specificity in detection by the noninvasive imaging technique positron emission tomography (PET) can be achieved by radiolabeling antibodies (Abs) designed to target tumor-associated antigens with increased expression post-translational modifications present in cancer cells. In this study, an Ab designed to target the transmembrane glycoprotein mucin 13 (MUC13) was radiolabeled with the positron-emitting radionuclide zirconium-89 (⁸⁹Zr) for PET imaging of a xenograft mouse model of CRC. Specified uptake of this radioimmunoconjugate was observed …

Two-Electron Density Of Three Electrons In A 1d Box: A Model System For Visualizing Spin Correlation Due To Antisymmetry Of Electrons, Joseph D. Alia

Chemistry Publications

Visual models for understanding electron density distribution in molecules are useful for chemical reasoning. The Lewis structure for example compares well to one-electron density when all electrons are paired. Linnett Double Quartet structures compare well to some kinds of free radical species. These approaches do not show the behavior of the total electron wavefunction when two electrons near each other. This behavior is a two- electron property and can be visualized with the model of three electrons in a one- dimensional box. The two-electron density of the three electron wavefunction described as a slater determinent of 1D particle-in-a-box spin- orbitals …

3d Pictorial Representations Of O2- And Ho2 Compared To Dft Results, Tzu-Hsiang Huang, Joseph D. Alia

Chemistry Publications

The Linnett Double Quartet (LDQ) (1) and Bohr Orbit Bonding (BOB) (2) methods were used to accurately represent the spin density distribution for superoxide (O2 -) and hydroperoxyl radical (HO2). These structural pictures were superimposed on the spin density plot produced by DFT. The Valency Interaction Formula (VIF) method (3) was also applied to these molecules and it matched the NBOs from NBO analysis of DFT results. The interaction between O2 - and H2O were analyzed and the stronger basicity of the beta-spin electrons of superoxide was identified by looking at the LDQ structure and confirmed with NBO analysis. The …

Limonene Enantiomeric Ratios From Anthropogenic And Biogenic Emission Sources, Shan Gu, Wentai Luo, Avisa Charmchi, Kevin J. Mcwhirter, Todd Rosenstiel, James F. Pankow

Chemistry Faculty Publications and Presentations

Emissions from volatile chemical products (VCPs) have been identified as contributors to air quality degradation in urban areas. Limonene can be a tracer compound for VCPs containing fragrances in densely populated regions, but limonene is also emitted from conifers that are planted in urban areas. This creates challenges for using limonene to estimate VCP emissions. In this study, the −/+ enantiomeric ratios of limonene from VCP and conifer emission sources were quantified to evaluate if this measurement could be used to aid in source apportionment and emission inventory development. Samples were analyzed using a gas chromatograph equipped with a chiral …

Analyzing Biomedical Datasets With Symbolic Tree Adaptive Resonance Theory, Sasha Petrenko, Daniel B. Hier, Mary A. Bone, Tayo Obafemi-Ajayi, Erik J. Timpson, William E. Marsh, Michael Speight, Donald C. Wunsch

Chemistry Faculty Research & Creative Works

Biomedical Datasets Distill Many Mechanisms Of Human Diseases, Linking Diseases To Genes And Phenotypes (Signs And Symptoms Of Disease), Genetic Mutations To Altered Protein Structures, And Altered Proteins To Changes In Molecular Functions And Biological Processes. It Is Desirable To Gain New Insights From These Data, Especially With Regard To The Uncovering Of Hierarchical Structures Relating Disease Variants. However, Analysis To This End Has Proven Difficult Due To The Complexity Of The Connections Between Multi-Categorical Symbolic Data. This Article Proposes Symbolic Tree Adaptive Resonance Theory (START), With Additional Supervised, Dual-Vigilance (DV-START), And Distributed Dual-Vigilance (DDV-START) Formulations, For The Clustering Of …

Cancer-Associated Fibroblast-Derived Acetate Promotes Pancreatic Cancer Development By Altering Polyamine Metabolism Via The Acss2–Sp1–Sat1 Axis, Divya Murthy, Kuldeep S. Attri, Surendra K. Shukla, Ravi Thakur, Nina V. Chaika, Chunbo He, Dezhen Wang, Kanupriya Jha, Aneesha Dasgupta, Ryan J. King, Scott E. Mulder, Joshua Souchek, Teklab Gebregiworgis, Vikant Rai, Rohit Patel, Tuo Hu, Sandeep Rana, Sai Sundeep Kollala, Camila Pacheco, Paul M. Grandgenett, Fang Yu, Vikas Kumar, Audrey J. Lazenby, Adrian R. Black, Susanna Ulhannan, Ajay Jain, Barish H. Edil, David L. Klinkebiel, Robert Powers, Amarnath Natarajan, Michael A. Hollingsworth, Kamiya Mehla2,, Quan Ly, Sarika Chaudhary, Rosa F. Hwang, Kathryn E. Wellen, Pankaj K. Singh

Robert Powers Publications

The ability of tumour cells to thrive in harsh microenvironments depends on the utilization of nutrients available in the milieu. Here we show that pancreatic cancer-associated fibroblasts (CAFs) regulate tumour cell metabolism through the secretion of acetate, which can be blocked by silencing ATP citrate lyase (ACLY) in CAFs. We further show that acetyl-CoA synthetase short-chain family member 2 (ACSS2) channels the exogenous acetate to regulate the dynamic cancer epigenome and transcriptome, thereby facilitating cancer cell survival in an acidic microenvironment. Comparative H3K27ac ChIP–seq and RNA–seq analyses revealed alterations in polyamine homeostasis through regulation of SAT1 gene expression and enrichment …

Basecol2023 Scientific Content, Dmitri Babikov

Chemistry Faculty Research and Publications

Context. The global context of making numerous data produced by researchers available requires collecting and organising the data, assigning meaningful metadata, and presenting the data in a meaningful and homogeneous way. The BASECOL database, which collects inelastic rate coefficients for application to the interstellar medium and to circumstellar and cometary atmospheres, meets those requirements.

Aims. We aim to present the scientific content of the BASECOL2023 edition.

Methods. While the previous versions relied on finding rate coefficients in the literature, the current version is populated with published results sent by the producers of data. The paper presents the …

Using Flipped Classroom Modules To Facilitate Higher Order Learning In Undergraduate Organic Chemistry, Lauren R. Holloway, Tabitha Miller, Bryce Da Camara, Paul M. Bogie, Briana L. Hickey, Jack Barbera, Angie L. Lopez, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

In an ongoing effort to incorporate active learning and promote higher order learning outcomes in undergraduate organic chemistry, a hybrid (“flipped”) classroom structure has been used to facilitate a series of collaborative activities in the first two courses of the lower division organic chemistry sequence. An observational study of seven classes over a five-year period reveals there is a strong correlation between performance on the in-class activities and performance on the final exam across all classes; however, a significant number of students in these courses continue to struggle on both the in-class activities and final exam. The Activity Engagement Survey …

The Α-Crystallin Chaperones Undergo A Quasi-Ordered Co-Aggregation Process In Response To Saturating Client Interaction, Kirsten Lampi, Adam P. Miller, Susan E. O'Neill, Steve L. Reichow

Chemistry Faculty Publications and Presentations

Small heat shock proteins (sHSPs) are ATP-independent chaperones vital to cellular proteostasis, preventing protein aggregation events linked to various human diseases including cataract. The α-crystallins, αA-crystallin (αAc) and αB-crystallin (αBc), represent archetypal sHSPs that exhibit complex polydispersed oligomeric assemblies and rapid subunit exchange dynamics. Yet, our understanding of how this plasticity contributes to chaperone function remains poorly understood. This study investigates structural changes in αAc and αBc during client sequestration under varying degree of chaperone saturation. Using biochemical and biophysical analyses combined with single-particle electron microscopy (EM), we examined αAc and αBc in their apo-states and at various stages of …

Dna-Based Assay For Calorimetric Determination Of Protein Concentrations In Pure Or Mixed Solutions, Matthew W. Eskew, Patrick Reardon, Albert S. Benight

Chemistry Faculty Publications and Presentations

It was recently reported that values of the transition heat capacities, as measured by differential scanning calorimetry, for two globular proteins and a short DNA hairpin in NaCl buffer are essentially equivalent, at equal concentrations (mg/mL). To validate the broad applicability of this phenomenon, additional evidence for this equivalence is presented that reveals it does not depend on DNA sequence, buffer salt, or transition temperature (Tm). Based on the equivalence of transition heat capacities, a calorimetric method was devised to determine protein concentrations in pure and complex solutions. The scheme uses direct comparisons between the thermodynamic stability of a short …