Biochemistry, Biophysics, and Structural Biology Commons^™

Chemical Synthesis Of Sensitive Dna, Komal Chillar

Dissertations, Master's Theses and Master's Reports

Over the past decades, researchers have tried various chemical methods to synthesize modified oligodeoxynucleotides (ODNs, i.e. short segments of DNAs). Traditional ODN synthesis methods require strong basic, and nucleophilic conditions for the deprotection and cleavage of the ODN from the solid support. However, the sensitive ODNs containing labile functionalities are vulnerable to such harsh conditions. Sensitive ODNs have a wide range of applications in research and pharmaceuticals. To synthesize sensitive ODNs, researchers devised different strategies but no practical methods have been developed. To overcome these challenges, we developed alkyl Dim alkyl Dmoc technology. This innovative technology uses weakly basic and …

Inhibition Of Src-3 As A Potential Therapeutic Strategy For Aggressive Mantle Cell Lymphoma, Imani Bijou, Yang Liu, Dong Lu, Jianwei Chen, Shelby Sloan, Lapo Alinari, David M Lonard, Bert W O'Malley, Michael Wang, Jin Wang

Faculty, Staff and Students Publications

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel …

Klebsiella Pneumoniae Carbapenemase Variant 44 Acquires Ceftazidime-Avibactam Resistance By Altering The Conformation Of Active-Site Loops, Zhizeng Sun, Hanfeng Lin, Liya Hu, Neetu Neetu, Banumathi Sankaran, Jin Wang, B V Venkataram Prasad, Timothy Palzkill

Faculty, Staff and Students Publications

Klebsiella pneumoniae carbapenemase 2 (KPC-2) is an important source of drug resistance as it can hydrolyze and inactivate virtually all β-lactam antibiotics. KPC-2 is potently inhibited by avibactam via formation of a reversible carbamyl linkage of the inhibitor with the catalytic serine of the enzyme. However, the use of avibactam in combination with ceftazidime (CAZ-AVI) has led to the emergence of CAZ-AVI-resistant variants of KPC-2 in clinical settings. One such variant, KPC-44, bears a 15 amino acid duplication in one of the active-site loops (270-loop). Here, we show that the KPC-44 variant exhibits higher catalytic efficiency in hydrolyzing ceftazidime, lower …

Exploring 3d Genome Interaction And Epigenetic Regulation Via Swi/Snf Complex And Deep Learning Models, Ruoyun Wang

Dartmouth College Ph.D Dissertations

The three-dimensional organization of the genome is fundamental in regulating gene expression and maintaining cellular function. This organization's complexities, influenced by epigenetic marks and chromatin remodeling complexes, are crucial for understanding genomic regulation. Among these, the SWI/SNF complexes are key, facilitating chromatin accessibility and regulating gene activity across cell types. The first part of my dissertation focuses on SWI/SNF complexes, exploring their role in chromatin remodeling and their impact on 3D genome architecture. Utilizing next-generation sequencing (NGS) techniques, this section investigates the interplay between these complexes and chromatin structure. During my research on the SWI/SNF complex, I was intrigued by …

A Multimolecular Perspective On The Success Of Wolf Recovery And Relocation, Samuel D. Hervey

Dissertations, Master's Theses and Master's Reports

With global biodiversity in decline and many species isolated in fragmented habitats, conservation efforts increasingly rely on natural recolonization and translocation to restore ecosystems. These strategies face challenges such as genetic erosion and habitat limitations, highlighting the need for effective monitoring practices. This research assesses the success of wolf recovery initiatives by examining long-term genetic and genomic health using both traditional and advanced molecular methods. First, we investigated the genetic health of 19 gray wolves (Canis lupus) relocated to Isle Royale National Park to restore ecosystem balance. Initial genetic assessments with microsatellites found that these wolves had genetic diversity metrics …

Synthesis Of Long Oligodeoxynucleotides, Yipeng Yin

Dissertations, Master's Theses and Master's Reports

Synthetic long oligodeoxynucleotides (ODNs) have found wide applications in diverse fields such as chemical biology, synthetic biology, and genes and genomes synthesis. Those applications leading to a significant demand for their production. However, traditional methods for purifying synthetic ODNs present notable drawbacks, particularly their inability to purify long ODNs, rendering long ODN synthesis challenging. To address these issues, chemical synthesis techniques for long ODNs coupled with non-chromatographic purification methods have been developed. This technology makes the purification of long synthetic ODNs feasible and offers a viable pathway for producing genes and genomes with extensive repeats or stable secondary structures, which …

Inactive Metallopeptidase Homologs: The Secret Lives Of Pseudopeptidases, Peter Lyons

Faculty Publications

Inactive enzyme homologs, or pseudoenzymes, are proteins, found within most enzyme families, that are incapable of performing catalysis. Rather than catalysis, they are involved in protein-protein interactions, sometimes regulating the activity of their active enzyme cousins, or scaffolding protein complexes. Pseudoenzymes found within metallopeptidase families likewise perform these functions. Pseudoenzymes within the M14 carboxypeptidase family interact with collagens within the extracellular space, while pseudopeptidase members of the M12 "a disintegrin and metalloprotease" (ADAM) family either discard their pseudopeptidase domains as unnecessary for their roles in sperm maturation or utilize surface loops to enable assembly of key complexes at neuronal synapses. …

Structural And Functional Analysis Of The Putatively Virulent Gene Products Tde1414, Tde1511, And Tde2714 From The Oral Pathogen Treponema Denticola, Brock W. Corbett

Theses and Dissertations (Comprehensive)

Periodontitis is a destructive polymicrobial disease of the teeth and gums characterized by dental plaque biofilms on the tooth surface, severe inflammation of surrounding gum tissues, and the resorption of alveolar bone. Discussed as one of the most prevalent conditions plaguing humankind, increased clinical parameters of periodontitis is associated with the increased presence of three bacteria known as the “red complex”: Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Various transcriptomic and proteomic studies of T. denticola when incorporated into mature biofilms have illuminated key gene targets the bacterium may use as virulence factors to aid in pathogenesis. …

Characterizing The Targeting Pathway Of Chloroplast Outer Membrane Protein Oep18 In Arabidopsis Thaliana And Other Targeting Signals Utilized By Outer Envelope Membrane Proteins, Ceaira Hiemstra

Theses and Dissertations (Comprehensive)

Approximately 95% of chloroplast proteins are encoded by nuclear DNA and are post-translationally targeted to the chloroplast. Over half of the 138 known or predicted chloroplast outer membrane (OM) proteins are predicted to utilize four non-canonical targeting pathways. The first two pathways are characterized by containing a single α-helical transmembrane domain (TMD) within the first or last 50 amino acids (AAs), the third pathway is utilized by β-barrels, and the last requires an N-terminal cleavable transit peptide (TP). Recently, a fifth novel pathway called Toc159-like (TOC159L) has been characterized by the presence of a C-terminal reverse TP in Toc159. Subsequent …

Pre-Left Ventricular Assist Device Endoscopic Evaluation Does Not Reduce The Risk Of Later Gastrointestinal Bleeding: A Multicenter Study, Jiahao Peng, Samanthika Devalaraju, Mohamed Azab, William T Cates, Molly Stone, Jonathan Reichstein, Sneha Shaha, Subhasis Chatterjee, Andrew B Civitello, Mourad H Senussi, B Joseph Elmunzer, Michael Volk, Wasseem Skef

Faculty, Staff and Students Publications

BACKGROUND: Gastrointestinal bleeding (GIB) is a common complication after placement of a left ventricular assist device (LVAD). Some institutions attempt to mitigate post-LVAD GIB using preoperative endoscopy. Our study evaluated whether preoperative endoscopy was associated with a lower risk of post-LVAD GIB.

METHODS: This was a multicenter cohort study of patients who underwent LVAD insertion from 2010-2019 at 3 academic sites. A total of 398 study participants were categorized based on whether they underwent preoperative endoscopy or not. The follow-up period was 1 year and the primary outcome was GIB. Secondary outcomes were severe bleeding and intraprocedural complications.

RESULTS: A …

Neurodevelopmental Vulnerability To Gestational Ozone Exposure, Vishnupriya Alavala, Sarah E. Brent, Christopher G. Canal, Joseph Wang, Russell P. Hunter, Matthew J. Campen, Andrew K. Ottens

Undergraduate Research Posters

Ambient air pollution accounts for about 4.2 million premature deaths annually per the World Health Organization. Ozone (O3) is a highly reactive air pollutant found in smog and is implicated in cellular damage leading to organ dysfunction. Ambient air pollution is associated with neurodevelopmental, behavioral, and cognitive disorders though ozone’s role is unknown. Studies here look at ozone exposure shortly after implantation vs. shortly before term to evaluate differences in neurodevelopmental susceptibility over time.

To inquire on the effects of ozone on the fetal brain, pregnant Sprague-Dawley rats were exposed once to 0.3 ppm of O3 or filtered air (FA) …

Novel Photobase Generators For Photoinduced Polymerization And Ph Regulation, Shupei Yu

Dissertations

Photochemistry encompasses the investigation of chemical processes instigated by light absorption. As important branches of photochemistry, photosensitive and optical materials have attracted extensive research interests in both academia and industry. Photosensitive and optical materials are composed of polymers / small molecules with photo-responsive properties. These materials not only can absorb light in the desired energy spectrum, but also exhibit chemical / physical reactions, which can be applied to different fields such as photoredox, photo-heat, phototherapy, solar cells, diodes, etc. Among them, photobase generators (PBGs) are a series of photosensitive compounds, which absorb the incident light, then release the basic species …

The Effect Of Walnut Shell Ash On The Properties Of Cement Paste And Mortar: A Study On Partial Replacement Of Cement, Ali Shebli, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

In the pursuit of a more sustainable future, the utilization of agricultural waste in cementitious products has emerged as a popular and effective solution. The current study explores the feasibility of incorporating ash derived from walnut nutshells, considered agro residues, into eco-friendly blended cement paste and mortars to examine its impact on their properties. A range of blended cement mixtures was formulated by incorporating walnut shell ash (WSA) in three varying proportions of 5%, 10%, and 15% relative to the weight of the cement. Tests were conducted to investigate the properties of the blended cement paste and mortar incorporating WSA, …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Comparative Histological Study On The Algerian Thymus Ciliatus At Different Phenological Stages, Nina Sadou, Ratiba Seridi, Hamdi Bendif

Journal of Bioresource Management

The aim of the current study was to compare the histological observations of stems, leaves, and different secretory structures of Thymus ciliatus at three phenological stages. The anatomical observations of stems, leaves, and glandular trichomes were carried out by light microscopy. The results showed that phenological stages do not affect significantly the anatomical, whereas there was a significant increase in secretory trichomes. The glandular trichomes are distributed on the surface of the stems and the leaves. There are only two distinct types of secretory trichomes, Peltate consisting of a basal cell, a stalk cell, and an 8-celled head type, which …

Structural Basis For Dna Proofreading, Gina Buchel, Ashok Nayak, Karl Herbine, Azadeh Sarfallah, Viktoriia Sokolova, Angelica Zamudio-Ochoa, Dmitry Temiakov

Department of Biochemistry and Molecular Biology Faculty Papers

DNA polymerase (DNAP) can correct errors in DNA during replication by proofreading, a process critical for cell viability. However, the mechanism by which an erroneously incorporated base translocates from the polymerase to the exonuclease site and the corrected DNA terminus returns has remained elusive. Here, we present an ensemble of nine high-resolution structures representing human mitochondrial DNA polymerase Gamma, Polγ, captured during consecutive proofreading steps. The structures reveal key events, including mismatched base recognition, its dissociation from the polymerase site, forward translocation of DNAP, alterations in DNA trajectory, repositioning and refolding of elements for primer separation, DNAP backtracking, and displacement …

The Mechanobiology Of Cell Plasticity, Yuan Hong

McKelvey School of Engineering Graduate Student Theses & Dissertations

The cell is a sophisticated machine, integrating chemical and physical inputs to decide upon the mechanobiological outputs that the body requires every second, in cardiomyocytes that make heartbeats, in fibroblasts that heal wounds, and in sarcomeres that contract muscles. Malfunction of mechanotransduction or mechanical inputs is implicated in diseases such as fibrosis, cancers, and cardiomyopathies, and a pressing quest is underway to unravel the intricacies of how mechanical force orchestrates the activation of cells. This dissertation explores these fundamental mechanisms of cell activation using integrated mathematical and engineered cell culture models. The work begins with the discovery that the directionality …

The Potential Of Stem Cell Therapy In Multiple Sclerosis Treatment: A Review, Sorina Amarculesei, Ava O'Meara Cushen, Cathy Brougham

SURE Journal: Science Undergraduate Research Experience Journal

Multiple Sclerosis is an autoimmune and neurodegenerative disease of the central nervous system. There are currently 2.8 million people living with Multiple Sclerosis worldwide, including 9000 people in Ireland, with a prevalence of 193 per 100,000 people. Symptoms of Multiple Sclerosis include sensory loss, fatigue, cognitive dysfunction, spasticity, depression, optic neuritis, gait ataxia, diplopia, and loss of bladder control. Currently, there is no standardised treatment or cure for Multiple Sclerosis with many strategies focusing on symptoms. Stem cells have emerged as promising approaches for Multiple Sclerosis therapeutics. Clinical trials primarily focus on mesenchymal stem cell-based therapies for Multiple Sclerosis. Furthermore, …

Creating Meaningful Connections With The Electron Transport Chain Beyond A Virtual Classroom, Lesley-Ann Giddings

Feminist Pedagogy

At the center of feminist pedagogy is community. Creating community within the classroom and between the class and local communities increases student engagement and access to knowledge. Communities can be a source of solidarity and further decenter authority in the classroom, empowering students, teachers, and the surrounding community to be co-learners. Amid the COVID-19 pandemic, remote teaching posed challenges to student engagement. Here, I describe an assignment used to build an inclusive community of co-learners within a virtual biochemistry class and our local communities. Oxidative phosphorylation is a cellular process used to create energy that depends on the electron transport …

Physically And Chemically‑Crosslinked L‑Arginine‑Loaded Polyvinyl Alcohol‑ Hyaluronic Acid‑ Cellulose Nanocrystals Hydrogel Membranes For Wound Healing: Influence Of Crosslinking Methods On Biological Performance Of Membranes In‑Vitro, Elbadawy A. Kamoun, Elbadawy A. Kamoun

Nanotechnology Research Centre

Two types of polyvinyl alcohol-blended hyaluronic acid and cellulose nanocrystals (PVA/HA/CNCs) hydrogels membranes were developed as delivery agents for L-arginine using chemical/and/physical crosslinking methods for exploring biological performance of the obtained membranes. Chemically and physically/crosslinked membranes were fabricated by solution-casting and freeze-thawing techniques, respectively. The characterization of the crosslinked PVA/HA/CNCs/Larginine membranes were conducted by SEM, FTIR, TGA, swelling ratio, and in—vitro L-arginine release. Furthermore, applying two types of crosslinked membranes in vitro were investigated in terms of cytotoxicity, hemocompatibility, and cell adhesion affinity of HFB-4 cell line. Chemical and physical-crosslinked membranes were verified through the esterification and hydrogen bonds interactions, …