Biochemistry Commons^™

Dendrimer Nanogels With Built-In Free Radical Scavenging Enable Efficient Topical Delivery Of A Hydrophilic Antioxidant To Restore Lens Redox Balance For Cataract Treatment, Lin Qi, Huari Kou, Anna Chernatynskaya, Da Huang, Vimalin Jeyalatha Mani, Humeyra Karacal, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

Cataract is a leading cause of vision impairment worldwide and are primarily caused by oxidative stress that damages and aggregates lens proteins, leading to lens opacification. However, the eye's anatomical barriers limit the penetration and bioavailability of antioxidant therapies. To address this challenge, a dendrimer-based nanogel with a built-in reactive oxygen species (ROS)-scavenging capability developed by us was employed to deliver the antioxidant N-acetylcysteine (NAC) to the lens. NAC was loaded into a generation-5 PEGylated poly(amidoamine) dendrimer (G5-PEG-TK, termed the GPT) nanogel. The resulting NAC-GPT was characterized for its ROS-scavenging activity, bioavailability, and corneal permeability. The efficacy of NAC-GPT was …

Optimizing Barley Stripped Mosaic Virus Coat Protein Stability For Palladium Nanorod Biotemplating Via Terminal His-Tag Positioning, Emilie Hayes

Honors Theses

Viral biotemplating has become an exciting approach towards the production of nanomaterials with a controlled size and morphology. Rod-shaped plant viruses provide structurally consistent scaffolds that can guide the assembly of inorganic nanostructures, which can offer a biologically inspired platform to nanoscale material design. In the current study, computational modeling was used to examine the effect of palladium precursor chemistry on the reaction with viral protein templates. Molecular dynamics simulations were performed to test the stability of the viral scaffold, and the influence of N-terminal and C-terminal His-tag on protein flexibility. These simulations revealed that the viral coat protein is …

Recombinant Gelonin: Purification And Functional Validation For Electroporation-Assisted Delivery, Eleni Zivla, Giedrė Šilkūnienė, Andrei G. Pakhomov, Mantas Šilkūnas, Olga N. Pakhomova

Knowledge and Creativity Expo

Type I ribosome-inactivating proteins, such as gelonin, are enzymatically potent toxins but are effectively non-toxic under physiological conditions because they are unable to cross the plasma membrane[1]. Pulsed electric fields (PEF) overcome this delivery barrier by transiently permeabilizing the plasma membrane, allowing direct cytosolic entry. This enhances gelonin cytotoxicity by several thousand-fold, highlighting gelonin’s potential as an electrochemotherapy candidate[2]. Here, we present a recombinant gelonin (rGel) expression platform in E. coli with HPLC-based purification that enables reproducible protein production and structure-guided engineering.

The mature gelonin sequence (residues 47–297) was cloned into pET-32a(+) with an N-terminally fused Trx-6×His tag and TEV …

Effect Of Novel Antimicrobial Compounds On Fungal And Bacterial Pathogens, Megan Wilderman

Honors Program: Senior Projects (Public)

Antimicrobial resistance is a growing concern in medicine¹ leading to a need for the development of novel compounds. Two compounds were tested in this study, 2-hydroxyethylhydrazine (HEH) and para-nitrophenyl-isocyanide (NPIC). HEH targets phosphatidylcholine (PC) production², and NPIC targets mitochondrial function³. Choline (Cho) is a compound that bypasses the inhibition of HEH through the Kennedy pathway.² Two-fold serial dilutions were conducted in 96-well plates to test the sensitivity of different bacteria to HEH and fungi to HEH and NPIC in different media types. A choline condition was also included in the HEH dilutions to test …

In Vitro And In Silico Analysis Of The Antibacterial Activity Of Bioactive Compounds Extracted From Pineapple Peel, Wafa Mohammad Sadik, Iman Tajer Abdullah, Lana Abed Alnajar

Makara Journal of Science

Antibiotic resistance is a critical global challenge that requires the discovery of alternative therapeutic agents. Plants -derived compounds, such as those found in Ananas comosus (pineapple)peel, offer promising antibacterial potential. This study aimed to evaluate the antibacterial activity of pineapple peel extract using both in vitro and in silico approaches. Ethanolic extracts of pineapple peel were fractionated using silica gel chromatography, and the resulting fractions were analyzed by GC-MS. Antibacterial activity was tested against Gram-positive and Gram-negative pathogens using the agar well diffusion method, and the inhibition zones were recorded. Molecular docking was performed to assess the interaction of identified …

Design And In Silico Modeling Of Heterocyclic-Based Xanthone Derivatives As Potential Anticancer Agents Through Tyrosine Kinase Inhibition, Yehezkiel Steven Kurniawan, Ervan Yudha, Nela Fatmasari, Radite Yogaswara, Harno Dwi Pranowo, Eti Nurwening Sholikhah, Jumina Jumina

Makara Journal of Science

Cancer is one of the deadliest diseases nowadays, and tyrosine kinase receptors play crucial roles in cancer cell survival, differentiation, proliferation, and migration. This study designed and developed a new inhibitor from heterocyclic-based xanthone derivatives to target two tyrosine kinase receptors, epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor (PDGFR), through in silico screening. Eighteen heterocyclic-based xanthones were evaluated through molecular docking for both receptors. All heterocyclic-based xanthones gave the root mean square deviation (RMSD) value lower than 2.00 Å. Xanthone with isobenzothiazole substituent (iBzThio) was found as the most potent inhibitor with binding energies of -10.60 and …

Interview With Orca Award Winner David Hage, Unl Chemistry; Drug-Protein Interactions, Mark Griep, David Hage

UNL ORCA Interview Series

Prof. David Hage was awarded the ORCA in 2018. He was born in La Crosse, Wisconsin, and earned a bachelor’s in chemistry at the University of Wisconsin in La Crosse. Next, he earned a doctorate from Iowa State University and did postdoctoral work at the Mayo Clinic in Rochester, Minnesota. In 1989, he joined UNL as an assistant professor of chemistry and quickly rose through the ranks. He has won many awards and, for the past 13 years, has been the James Hewet University Professor of Chemistry. Allow me to share some remarkable facts about Dave before we get into …

Role Of Wadsley Defects And Cation Disorder To Enhance Monb12O33 Diffusion, Cj Sturgill, Manish Kumar, Nima Karimitari, Iva Millisavljevic, Coby S. Collins, Aaron Hegler, Hsin-Yun Joy Chao, Santosh Kiran Balijepalli, Scott T. Misture, Christopher Sutton, Morgan Stefik

Faculty Publications

Wadsley-Roth (WR) niobates have emerged as high-rate anode materials that can combine rapid ionic diffusion with good electronic conductivity. WR compounds have been defect-enhanced by limited annealing, however, such materials often contain multiple types of defects. In particular, both Wadsley defects (variable block size) and transition metal disorder have the potential to modify transport rates, however the corresponding effects are not well understood mechanistically. Here, MoNb12O33 (MNO) was calcined at two different temperatures to compare a defect-rich condition (MNO-800) with a proximal order-rich condition (MNO-900) as assessed through XRD, XANES, EXAFS, and STEM characterizations. Galvanostatically cycled lithium half cells of …

The Molecular Determinants Of Deglycation And Substrate Specificity In Fructosamine Kinases, Jenet Matlack

USF Tampa Graduate Theses and Dissertations

Protein glycation is a universal, non-enzymatic modification that occurs when a sugar covalently attaches to a primary amine. These spontaneous modifications may have deleterious or regulatory effects on protein function, and their removal is mediated by the conserved metabolic kinase fructosamine-3-kinase (FN3K). Despite its crucial role in protein repair, we currently have a poor understanding of how FN3K engages or phosphorylates its substrates. Additionally, the molecular basis for the distinct yet overlapping substrate specificities of FN3K and its paralog, ketosamine-3 kinase (KT3K), remains unresolved. By integrating structural biology, biochemistry, and ancestral protein reconstruction (APR), this thesis elucidates the catalytic mechanism …

Tlr3 Mediated Type I Interferon Response In Mammalian Cell Defense Against Cryptosporidium Parvum Infection., Anjelica Matias

Biochemistry and Molecular Biology

Cryptosporidium parvum is a major cause of a diarrheal disease which affects many children in the USA as well as the rest of the world, yet the contribution of its double stranded RNA (dsRNA) viral symbiont, Cryspovirus (CSpV1) to host innate immunity remains unclear. This study investigated whether CSpV1 activates Toll Like Receptor 3 (TLR3) signaling pathways and downstream Interferon type I (IFN I) responses in mammalian intestinal epithelial cells. Confluent Human Ileocecal Colorectal Adenocarcinoma cells (HCT8) were exposed to CSpV1, and the expression levels of Tumor Necrosis Factor Receptor-Associated Factor 3 (TRAF3), Nuclear Factor-𝜅-light chain enhancer of activated B-cells …

Contribution Of G4 Structure To Alzheimer’S Disease And Tau Pathology, Lena Michaela Kallweit

Electronic Theses and Dissertations

The occurrence of Alzheimer’s Disease (AD) is rapidly increasing as our global population ages. With the majority of therapeutic drugs in the last couple of decades failing clinical trials, new molecular targets are needed to combat the expected influx of new AD cases. AD pathogenesis is associated with abnormal protein aggregation, characterized in part by intracellular accumulation of hyperphosphorylated tau (p-tau) in neurofibrillary tangles (NFTs). RNA has been identified as a major non-proteinaceous component of NFTs and has been implicated as an active cofactor in tau aggregation and spread. Recent work has shown that aggregates from AD brains contain almost …

Polθ Activity Modulates Sensitivity To Standard Therapies In Dnmt3a-Deficient Leukemia, Bac Viet Le, Umeshkumar Vekariya, Monika M. Toma, Margaret Nieborowska-Skorska, Marie-Christine Caron, Malgorzata Gozdecka, Zayd Haydar, Martin Walsh, Jayashri Ghosh, Elaine Vaughan-Williams, Paulina Podszywalow-Bartnicka, Anna-Mariya Kukuyan, Sylwia Ziolkowska, Jessica Atkins, Emir Hadzijusufovic, Gurushankar Chandramouly, Reza Nejati, Katarzyna Piwocka, Richard T. Pomerantz, George S. Vassiliou, Brian J.P. Huntly, Peter Valent, Mariusz Wasik, Alfonso Bellacosa, Jean-Yves Masson, Gaorav P. Gupta, Grant A. Challen, Tomasz Skorski

Department of Biochemistry and Molecular Biology Faculty Papers

Myeloid malignancies carrying somatic DNMT3A mutations (DNMT3Amut) are refractory to standard therapy. DNMT3Amut leukemia cells accumulate toxic DNA double-strand breaks (DSBs) and stalled replication forks, rendering them dependent on DNA damage response (DDR). We report here that DNA polymerase theta (Polθ), a key element in DSB repair by end-joining (Polθ-mediated end-joining [TMEJ]) and in fork restarting, promotes survival and proliferation of DNMT3Amut leukemia cells. Polθ is overexpressed in DNMT3Amut leukemia cells due to abrogation of PARP1 PARylation-dependent UBE2O E3 ligase-mediated ubiquitination and proteasomal degradation of Polθ. In addition, PARP1-mediated recruitment of the SMARCAD1-MSH2/MSH3 repressive complex to DSBs is diminished in …

Main-Chain Ion-Pair Polybenzimidazole Membranes Enabling Reduced-Temperature Ht-Pemfc Operation (Down To 120°C), Huina Lin, Brian C. Benicewicz

Faculty Publications

Proton exchange membrane (PEM) fuel cells are promising for clean and efficient energy conversion across diverse applications. High-temperature PEM fuel cells (HT-PEMFCs) using phosphoric acid (PA)-doped polybenzimidazole (PBI) can operate up to 200°C, but at lower temperatures, water-induced PA loss often leads to performance degradation and reduced durability. In this work, we present a new class of main-chain ion-pair PBI membranes by integrating the imidazolium-biphosphate ion-pair units directly into the PBI backbone. This design results in membranes with high acid content, stronger acid-polymer interactions and stabilized acid retention. In single-cell tests, the Im⁺-PBI15-3 wt.% exhibits peak power densities …

Exosome Engineering For Blocking Gut Dysbiosis And Inducing Cell Death Mechanisms In Glioblastoma Multiforme, Ahalya Muraleedharan, Karthik Rangavajhula, Swapan K. Ray

Faculty Publications

Glioblastoma multiforme (GBM) is the most lethal primary brain tumor in adults. Emerging evidence endorses that gut dysbiosis contributes to GBM progression through the gut–brain axis (GBA), promoting inflammation and therapeutic resistance via abnormal short-chain fatty acid production and cytokine dysregulation. Exosomes, naturally occurring nanovesicles (30–150 nm), offer promising therapeutic potential due to their blood–brain barrier permeability, biocompatibility, and versatile cargo capacity. This review examines exosome engineering strategies for dual targeting: inhibiting alterations in gut microbiome and inducing regulated cell death mechanisms such as apoptosis and ferroptosis in GBM. We describe exosome engineering with detailed focus on cargo loading approaches …

Rapid Single-Cell Measurement Of Transient Transmembrane Water Flow Under Osmotic Gradient, Hong Jiang, Jinnawat Jongkhumkrong, Y. J. Chao, Qian Wang, Guiren Wang

Faculty Publications

Aquaporins (AQPs) are critical for transmembrane water transport in response to osmotic gradients, but their gating and regulatory mechanisms remain poorly understood. A central challenge is the lack of methods to measure water flow across AQPs from individual cells with the spatiotemporal resolution and sensitivity equivalent to patch-clamp recordings of ion fluxes—a limitation stemming from the electrically silent nature of water flow. Here, we present a novel optical technique—Flow-Induced Fluorescence Increase Velocimetry (FIFIV) based on Laser-Induced Fluorescence Photobleaching Anemometry (LIFPA)—that enables direct, real-time monitoring of cytoplasmic flow induced by transmembrane water transport under osmotic pressure gradients. Using small molecular fluorescent …

The Structure, Pathogenesis, And Inhibition Of The P53-Mdm2 Pathway, Amanda L. Brown, Xiaoying Lian, Qian Wang

Faculty Publications

The p53 tumor suppressor protein plays a central role in maintaining genomic stability by regulating cell cycle arrest, apoptosis, and DNA repair under cellular stress. Mouse double minute 2 (MDM2), an E3 ubiquitin ligase, negatively regulates p53 via direct binding and proteasomal degradation. Overexpression or amplification of MDM2 can disrupt this pathway and promote tumorigenesis, even in cancers with wild-type p53. This review outlines the structural features of MDM2, particularly its N-terminal hydrophobic pocket and C-terminal RING domain, and their roles in p53 regulation. We further examine the pathological effects of MDM2 dysregulation and SNPs linked to increased cancer risk. …

Ecologic Factors Contributing To West Nile Virus Hyperendemicity In Central South Carolina: An Integrated Vector–Human–Environmental Study, Elba S. Fridriksson, Ahayla Muraleedharan, Kyndall C. Dye-Braumuller, Madeleine M. Meyer, Kia Zellars, Hiuxuan Li, Melissa S. Nolan Ph.D., Mph

Faculty Publications

West Nile virus (WNV) is an endemic arboviral infection in the United States that has undergone phyloge-netic evolution since its introduction 25 years ago. An integrated vector–human–pathogen study was conducted in the summer of 2023 to unearth contemporary Culex quinquefasciatus habitat patterns and human transmission spillover foci in South Carolina, a state with historically little WNV data. A serosurvey revealed WNV seroprevalence 10 times the national average (22% versus 2%, respectively), with unusual epidemiologic risk factors. Female Culex quinquefas-ciatus WNV positivity was low (2.7%), with viral phylogenetics 100% homologous to the WN02 clade. Mosquito vectors clustered in affluent urban neighborhoods …

Boronate Esters For The Binding And Detection Of Low Molecular Weight Volatile Amines, Xiaoning Li, James Boyt, Steven Sloope, Luke T. Lackovic, Mark D. Smith, James J. Lavingne

Faculty Publications

Conjugated thiophene-based diboronate esters, 1–4, were synthesized to investigate how substituents on catechol alter the Lewis acidity and accessibility to boron, and influence binding interactions with low molecular weight Lewis basic amines. Crystallographic analysis indicated that both boron centres bind analyte and that Lewis base coordination induces deplanarization of the conjugated system. Spectroscopic studies demonstrate that amine binding disrupts conjugation, producing distinct and reproducible optical responses that depend on analyte basicity and structure, with association constants in organic solvent ranging from 10³ to 10⁶ M⁻¹. Quantitative binding analyses indicate strong negative cooperativity between the two boron …

Characterization And Advancement Of Molluscan Venom Gland Cell Model Systems, James V. Parziale

Dissertations, Theses, and Capstone Projects

Venomous mollusks, including cone snails and coleoid cephalopods, produce rich repertoires of bioactive peptides with profound effects on cellular physiology, yet there are few tractable experimental systems that exist to study their development, maintenance, and venom secretion. Although therapeutics such as the cone snail peptide Ziconotide demonstrate the biomedical potential of molluscan venoms, progress in understanding how venom glands form, function, and evolve has been hindered by the lack of reliable husbandry and the complete absence of in vitro cell models. Modern comparative genomics has revealed widespread convergent evolution across venomous lineages, but molluscan datasets remain underrepresented, limiting insights into …

Impact Of Iron-Bearing Fillers On The Mechanical Strength And Chemical Stability Of Magnesium Potassium Phosphate Matrices Incorporating Rhenium, Sergey Sayenko, Volodymyr Shkuropatenko, Hans Conrad Zur Loye, Petr Vecernik, Monika Kiselova, Vlastislav Kašpar, Vlastimil Miller, Petr Bezdicka, Jan Šubrt, Petra Ecorchard, Natalija Murafa, Iva Milisavljevic, Scott T. Misture

Faculty Publications

We report on the study of the immobilization process of non-radioactive rhenium (Re), a chemical analogue of technetium-99 (⁹⁹Tc), in compounds based on magnesium potassium phosphate (MKP), as well as the possibility of enhancing their properties with iron-bearing additives/fillers. Powdered Re2O7 was used as the initial Re-containing source. Because of the solubility and high leachability of Tc (VII), which is also volatile at high temperatures, its immobilization for long-term storage and disposal poses a serious challenge to researchers. Taking this into account, low-temperature stabilization technology based on MKP, a cementitious material, is currently considered promising. We prepared experimental …