Biochemistry, Biophysics, and Structural Biology Commons^™

Mechanistic Investigations Of A Novel Braf Regulatory Switch And Braftide, An Allosteric Peptide Inhibitor Of Braf, Alison Yu

Theses and Dissertations

RAF kinases (ARAF/BRAF/CRAF or Raf-1) are serine/threonine kinases in the MAPK (RAS-RAF-MEK-ERK) pathway. The MAPK pathway is crucial in development and normal cell function. These same roles are dysregulated in cancer; BRAF is the most frequently mutated isoform in cancers and in particular, activation loop mutants BRAF V600E/K mutants have the highest mutational incidence. Three FDA approved inhibitors potently inhibit BRAF V600E/K mutants. However, these same inhibitors fail to address the non-V600E/K mutations and result in paradoxical activation of the MAPK pathway. Two strategies were employed to address the limitations of the FDA-approved inhibitors: provide novel regulatory details of RAF …

A Naturally Derived Watercress Flower-Based Phenethyl Isothiocyanate-Enriched Extract Induces The Activation Of Intrinsic Apoptosis Via Subcellular Ultrastructural And Ca2+ Efflux Alterations In An In Vitro Model Of Human Malignant Melanoma, Sotiris Kyriakou, Louiza Potamiti, Nikoletta Demosthenous, Tom Amery, Kyle Stewart, Paul G. Winyard, Rodrigo Franco, Aglaia Pappa, Mihalis I. Panayiotidis

School of Veterinary and Biomedical Sciences: Faculty Publications

The aim of the current study was to (i) extract isolated fractions of watercress flowers enriched in polyphenols, phenethyl isothiocyanate and glucosinolates and (ii) characterize the anticancer mode of action of non-lethal, sub-lethal and lethal concentrations of the most potent extract fraction in primary (A375) and metastatic (COLO-679) melanoma cells as well as non-tumorigenic immortalized keratinocyte (HaCaT) cells. Cytotoxicity was assessed via the Alamar Blue assay, whereas ultrastructural alterations in mitochondria and the endoplasmic reticulum were determined via transmission electron microscopy. Mitochondrial membrane depolarization was determined using Mito-MP dye, whereas apoptosis was evaluated through the activation of caspases-3, -8 and …

Color Stability, Physical Properties And Antifungal Effects Of Zro2 Additions To Experimental Maxillofacial Silicones: Comparisons With Tio2, Mazen Alkahtany, Mark W. Beatty, Fahd Alsalleeh, Thomas M. Petro, Bobby Simetich, You Zhou, Dennis Feely, Grigoris Polyzois

School of Veterinary and Biomedical Sciences: Faculty Publications

(1) Background: Color changes, physical degradation, and fungal infections are challenges to the longevity of maxillofacial polydimethylsiloxane (PDMS) elastomers. This study aimed to evaluate color changes, physical properties, and antifungal properties of PDMS loaded with ZrO₂ and TiO₂ submicron- and nano-sized particles. (2) Methods: A 1% weight of 40 nm or 200 nm diameter ZrO₂ or TiO₂ nanoparticles was mixed into PDMS with 2% functional intrinsic yellow pigment and polymerized. Control materials contained 13% weight 200 nm silica. Samples were exposed to 3000 h of UVB radiation (200 μW/cm²) or darkness. Color parameters L*a*b* …

Development Of Bioactive Peptidomimetics, Lei Wang

USF Tampa Graduate Theses and Dissertations

In the past two decades, a lot of different peptidomimetics, such as β-peptides, oligoureas, azapeptides, peptoids, aromatic oligoamides, and others, have been developed. These peptidomimetics with distinctive scaffolds have shown potential in protein surface recognition and mimicry, PPI regulation, catalysis, etc. Moreover, these bioactive peptidomimetics demonstrate much better bioavailability and biostability than the bioactive peptides. To expand the application of peptidomimetics, our group have developed a new sequence-specific peptidomimetics- γ-AApeptide, which is derived from chiral γ-PNA. It shows excellent advantages including highly resistant to various proteolytical degradations and has the potential to increase chemodiversity. γ-AApeptide also exhibits remarkable biomedical applications, …

Hiv-1 Vpu Protein Forms Stable Oligomers In Aqueous Solution Via Its Transmembrane Domain Self-Association, Saman Majeed, Lan Dang, Md Majharul Islam, Olamide Ishola, Peter P Borbat, Steven J Ludtke, Elka R Georgieva

Faculty, Staff and Students Publications

We report our findings on the assembly of the HIV-1 protein Vpu into soluble oligomers. Vpu is a key HIV-1 protein. It has been considered exclusively a single-pass membrane protein. Previous observations show that this protein forms stable oligomers in aqueous solution, but details about these oligomers still remain obscure. This is an interesting and rather unique observation, as the number of proteins transitioning between soluble and membrane embedded states is limited. In this study we made use of protein engineering, size exclusion chromatography, cryoEM and electron paramagnetic resonance (EPR) spectroscopy to better elucidate the nature of the soluble oligomers. …

Development Of Antiviral Peptidomimetics, Songyi Xue

USF Tampa Graduate Theses and Dissertations

Protein-protein interactions (PPIs) are essential for biological processes and are associated with a number of diseases, including cancer, infectious diseases, and neurodegenerative diseases. As a result, modulation of PPIs has been recognized as one of the most promising strategies to develop the novel drugs. Peptide modulators always exhibit higher specificity and affinities with targets than small compounds or monoclonal antibodies, but their broad medicinal effectiveness is constrained by their poor bioavailability and biostability. Peptidomimetics, which have been developed to mimic the structure as well as function of bioactive peptides and proteins, have shown excellent potential in protein surface mimicry and …

Selected Fermented Indigenous Vegetables And Fruits From Malaysia As Potential Sources Of Natural Probiotics For Improving Gut Health, Olaide Olawunmi Ajibola, Raymond Thomas, Babatunde Femi Bakare

Biochemistry Publications

In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant …

Molecular Mechanisms Regulating Prometaphase And Metaphase States For Faithful Chromosome Segregation, Sarah Yvette Valles

Dartmouth College Ph.D Dissertations

Cells progress through different stages of the cell cycle as they ultimately prepare to divide during mitosis. Mitosis relies on many interconnected networks to carry out the coordinated events required for faithful chromosome segregation. When a cell enters mitosis, chromosomes are highly condensed and sister chromatids are held together by cohesion. Kinetochores assemble at the constricted regions on each chromosome. The kinetochore is a large macromolecular structure composed of many proteins that form the binding site for microtubules of the mitotic spindle to attach. These kinetochore-microtubule (k-MT) attachments serve to align chromosomes at the center of the cell and are …

Protocol For Optimizing Production And Quality Control Of Infective Ecohiv Virions, Hammodah Rawhi Hammodah Alfar, Daphne N. Pariser, Harry Chanzu, Smita Joshi, Daniёlle M. Coenen, Joshua Lykins, Kanakanagavalli Shravani Prakhya, Mary Jane Potash, Wei Chao, Jennifer Kelschenbach, David J. Volsky, Kelly Metcalf-Pate

Saha Cardiovascular Research Center Faculty Publications

EcoHIV is a model of HIV infection that recapitulates aspects of HIV-1 pathology in mice. However, there are limited published protocols to guide EcoHIV virion production. Here, we present a protocol for producing infective EcoHIV virions and essential quality controls. We describe steps for viral purification, titering, and multiple techniques to analyze infection efficacy. This protocol produces high infectivity in C57BL/6 mice which will aid investigators in generating preclinical data.

A Novel Grk3-Hdac2 Regulatory Pathway Is A Key Direct Link Between Neuroendocrine Differentiation And Angiogenesis In Prostate Cancer Progression, Samira Naderinezhad, Guoliang Zhang, Zheng Wang, Dayong Zheng, Mohit Hulsurkar, Michael Bakhoum, Ning Su, Han Yang, Tao Shen, Wenliang Li

Faculty, Staff and Students Publications

The mechanisms underlying the progression of prostate cancer (PCa) to neuroendocrine prostate cancer (NEPC), an aggressive PCa variant, are largely unclear. Two prominent NEPC phenotypes are elevated NE marker expression and heightened angiogenesis. Identifying the still elusive direct molecular links connecting angiogenesis and neuroendocrine differentiation (NED) is crucial for our understanding and targeting of NEPC. Here we found that histone deacetylase 2 (HDAC2), whose role in NEPC has not been reported, is one of the most upregulated epigenetic regulators in NEPC. HDAC2 promotes both NED and angiogenesis. G protein-coupled receptor kinase 3 (GRK3), also upregulated in NEPC, is a critical …

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 …

Nurse Leader Perceptions Of Data In The Veterans Health Administration: A Qualitative Evaluation, Janine J Wong, Richard P Sorelle, Christine Yang, Melissa K Knox, Sylvia J Hysong, Lynette E Dorsey, Patrick N O'Mahen, Laura A Petersen

Faculty, Staff and Students Publications

Healthcare systems and nursing leaders aim to make evidence-based nurse staffing decisions. Understanding how nurses use and perceive available data to support safe staffing can strengthen learning healthcare systems and support evidence-based practice, particularly given emerging data availability and specific nursing challenges in data usability. However, current literature offers sparse insight into the nature of data use and challenges in the inpatient nurse staffing management context. We aimed to investigate how nurse leaders experience using data to guide their inpatient staffing management decisions in the Veterans Health Administration, the largest integrated healthcare system in the United States. We conducted semistructured …

Oral Delivery Of Rnai For Cancer Therapy, Humayra Afrin, Renu Geetha Bai, Raj Kumar, Sheikh Shafin Ahmad, Sandeep K Agarwal, Md Nurunnabi

Faculty, Staff and Students Publications

Cancer is a major health concern worldwide and is still in a continuous surge of seeking for effective treatments. Since the discovery of RNAi and their mechanism of action, it has shown promises in targeted therapy for various diseases including cancer. The ability of RNAi to selectively silence the carcinogenic gene makes them ideal as cancer therapeutics. Oral delivery is the ideal route of administration of drug administration because of its patients' compliance and convenience. However, orally administered RNAi, for instance, siRNA, must cross various extracellular and intracellular biological barriers before it reaches the site of action. It is very …

Factors Influencing Prescribing The First Add-On Disease-Modifying Antirheumatic Drugs In Patients Initiating Methotrexate For Rheumatoid Arthritis, Yinan Huang, Satabdi Chatterjee, Sandeep K Agarwal, Hua Chen, Michael L Johnson, Rajender R Aparasu

Faculty, Staff and Students Publications

BACKGROUND: Advances in Disease-Modifying Antirheumatic Drugs (DMARDs) have expanded the treatment landscape for Rheumatoid Arthritis (RA). Guidelines recommend adding either conventional synthetic (cs), biologic (b), or targeted synthetic (ts) DMARDs to methotrexate (MTX) for managing RA. Limited evidence exists regarding the factors that contribute to adding a DMARD agent to the MTX regimen. This study examined the factors associated with adding the first DMARD in RA patients initiating MTX.

METHODS: This retrospective cohort study utilized the MarketScan data (2012-2014) involving adults (aged ≥18) with RA initiating an MTX (index date) between Jul 1, 2012 and Dec 30, 2013, and with …

The Transcription Factor Chrebp Links Mitochondrial Lipidomes To Mitochondrial Morphology And Progression Of Diabetic Kidney Disease, Li Li, Jianyin Long, Koki Mise, Naravat Poungavrin, Philip L Lorenzi, Iqbal Mahmud, Lin Tan, Pradip K Saha, Yashpal S Kanwar, Benny H Chang, Farhad R Danesh

Faculty, Staff and Students Publications

A substantial body of evidence has established the contributions of both mitochondrial dynamics and lipid metabolism to the pathogenesis of diabetic kidney disease (DKD). However, the precise interplay between these two key metabolic regulators of DKD is not fully understood. Here, we uncover a link between mitochondrial dynamics and lipid metabolism by investigating the role of carbohydrate-response element-binding protein (ChREBP), a glucose-responsive transcription factor and a master regulator of lipogenesis, in kidney podocytes. We find that inducible podocyte-specific knockdown of ChREBP in diabetic db/db mice improves key biochemical and histological features of DKD in addition to significantly reducing mitochondrial fragmentation. …

Changes In The Epigenetic Landscape Of Oligodendrocyte Progenitor Cells With Time, David K. Dansu

Dissertations, Theses, and Capstone Projects

Most neonatal oligodendrocyte progenitors (nOPCs) give rise to myelinating oligodendrocytes during development, while a proportion are retained as proliferative undifferentiated cells in the adult brain (aOPCs). Previous studies have reported distinct properties for those two populations but the molecular mechanisms underlying these intrinsic differences are not well understood. Using RNA-sequencing and unbiased histone proteomics analysis, we identify transcripts and histone marks that are higher in aOPCs than nOPCs. The genome-wide ChIP-sequencing analysis of chromatin from aOPCs compared to nOPCs detects greater occupancy of the H4K8ac mark at loci corresponding to the higher transcript levels of oligodendrocyte-specific transcription factors and lipid …

The Minimal Suf System Is Not Required For Fe–S Cluster Biogenesis In The Methanogenic Archaeon Methanosarcina Acetivorans, Jasleen Saini, Thomas M. Deere, Daniel J. Lessner

Biological Sciences Faculty Publications and Presentations

Iron–sulfur (Fe–S) proteins are essential for the ability of methanogens to carry out methanogenesis and biological nitrogen fixation (diazotrophy). Nonetheless, the factors involved in Fe–S cluster biogenesis in methanogens remain largely unknown. The minimal SUF Fe–S cluster biogenesis system (i.e., SufBC) is postulated to serve as the primary system in methanogens. Here, the role of SufBC in Methanosarcina acetivorans, which contains two sufCB gene clusters, was investigated. The CRISPRi-dCas9 and CRISPR-Cas9 systems were utilized to repress or delete sufC1B1 and sufC2B2, respectively. Neither the dual repression of sufC1B1 and sufC2B2 nor the deletion of both sufC1B1 and sufC2B2 …

Singlet Oxygen-Mediated Conformational Flexibility, Antioxidant, And Isomerization Studies In Chemistry And Biochemistry, Oliver Turque

Dissertations, Theses, and Capstone Projects

Three chapters are included in this dissertation, each of which describes non-oxidative reactions, with peroxy intermediates formed between singlet oxygen (¹O₂) and substrate. (1) Novel discoveries related to the intermediate formed by ¹O₂ and dimethyl disulfane are explored. (2) A new mechanism is proposed, wherein the dihedral angle CS–SC (θ) determines the pro- or antioxidant activity of an organic disulfide. (3) A review of ¹O₂'s ability to facilitate the geometric isomerization of alkenes and polyenes is presented in Chapter 3.

Chapter 1 investigates the role of singlet oxygen potentially …

Characterization Of Pathological Tau Mutants, Charles J. Mcdonald

Dissertations, Theses, and Capstone Projects

Tau is a protein expressed exclusively in glia and neurons in the central nervous system and implicated in several neurogenerative diseases called “tauopathies”. Among all the tauopathies, one third is characterized by the presence of genetic mutations leading to the synthesis of tau proteins with single amino acid substitutions at specific locations and affecting protein function. While most of the initial studies have emphasize the functional role of tau as modulator of the axonal cytoskeleton, it has recently been well accepted that tau is also an intrinsically disordered protein that tends to form membraneless organelles called coacervates, due to a …

Characterization And Modulation Of The Emergent Material Properties Of Biomolecular Condensates, Alfredo Vidal Ceballos

Dissertations, Theses, and Capstone Projects

The discovery of membraneless organelles has revolutionized the field of cell biology and our understanding of cell compartmentalization. These organelles lack a distinct phospholipid bilayer and interact with the cytoplasm mediated by a liquid-liquid interface. The emergent properties and characterization of these organelles are essential for decoding the mechanisms underlying their function and dysfunction. In this thesis, we focus on two reconstituted in-vitro model systems of protein condensates and advance current methodology in order to address these fundamental questions. The first model system examined is the neuronal granule protein Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein, that aids …

Magnetically-Driven Therapeutic Agents Delivery System Using Iron Oxide Nanocages And Enhancement Of Exosome Secretion, A Potential Biological Drug Delivery Carrier, Min A Kang

Dissertations, Theses, and Capstone Projects

Nano-scale particles have attracted research attention due to their differences in properties such as penetration, circulation, and toxicity compared to bulk materials. This thesis mainly focused on using 20 nm iron oxide nanoparticles as siRNA delivery carriers under the alternating magnetic field and the development of a method to amplify the secretion of 150 nm exosomes from the cells, which could potentially use as a biological drug carrier.

Chapter 2 discusses a magnetically driven nanoparticle therapeutic agent delivery system, which efficiently modified the gene expression post-transcriptionally. In this work, we examined whether the caged-shaped 20nm iron oxide nanoparticles (IO-nanocages) can …

Out-Of-Distribution Generalization Of Deep Learning To Illuminate Dark Protein Functional Space, Tian Cai

Dissertations, Theses, and Capstone Projects

Dark protein illumination is a fundamental challenge in drug discovery where majority human proteins are understudied, i.e. with only known protein sequence but no known small molecule binder. It's a major road block to enable drug discovery paradigm shift from single-targeted which looks to identify a single target and design drug to regulate the single target to multi-targeted in a Systems Pharmacology perspective. Diseases such as Alzheimer's and Opioid-Use-Disorder plaguing millions of patients call for effective multi-targeted approach involving dark proteins. Using limited protein data to predict dark protein property requires deep learning systems with OOD generalization capacity. Out-of-Distribution (OOD) …

Construction And Performance Optimization Of Bioconjugated Nanosensors For Early Detection Of Breast Cancer And Pro-Inflammatory Diseases, Pooja Gaikwad

Dissertations, Theses, and Capstone Projects

In recent years, nanosensors have emerged as a tool with strong potential in medical diagnostics. Single-walled carbon nanotube (SWCNT) based optical nanosensors have notably garnered interest due to the unique characteristics of their near-infrared fluorescence emission, including tissue transparency, photostability, and various chiralities with discrete absorption and fluorescence emission bands. Additionally, the optoelectronic properties of SWCNT are sensitive to the surrounding environment, which makes them suitable for in vitro and in vivo biosensing. Single-stranded (ss) DNA-wrapped SWCNTs have been reported as optical nanosensors for cancers and metabolic diseases. Breast cancer and cardiovascular diseases are the most common causes of death …

Characterization Of The Conformational Binding Of N-Methyl Mesoporphyrin Ix With Dna Model Telomeric G-Quadruplex Forming Sequences, Jessica Desamero

Dissertations, Theses, and Capstone Projects

DNA G-quadruplexes are alternative secondary structures formed from guanine rich DNA sequences. G-quadruplexes are found most abundantly at the ends of chromosomes called telomeres, where they can ultimately prevent further tumor growth and progression. Thus, quadruplex interactive agents, or ligands that can bind to and stabilize DNA G-quadruplex structures, are of high interest for their potential chemotherapeutic abilities. One quadruplex interactive agent is the porphyrin N-methyl mesoporphyrin IX (NMM), which has high binding selectivity for quadruplex structures. While the NMM-quadruplex complex in crystallized form has been greatly studied, this complex in solution form is not as well studied. Through circular …

Optimization And Application Of Graph Neural Networks, Shuo Zhang

Dissertations, Theses, and Capstone Projects

Graph Neural Networks (GNNs) are widely recognized for their potential in learning from graph-structured data and solving complex problems. However, optimal performance and applicability of GNNs have been an open-ended challenge. This dissertation presents a series of substantial advances addressing this problem. First, we investigate attention-based GNNs, revealing a critical shortcoming: their ignorance of cardinality information that impacts their discriminative power. To rectify this, we propose Cardinality Preserved Attention (CPA) models that can be applied to any attention-based GNNs, which exhibit a marked improvement in performance. Next, we introduce the Directional Node Pair (DNP) descriptor and the Robust Molecular Graph …

Structural Basis Of Signal Transduction Within Environmental Sensing Pas Regulated Ser/Thr Kinases, Roksana Azad

Dissertations, Theses, and Capstone Projects

To sense environmental cues, nature has evolved molecular switches that are widely used across life. This process often relies on environmentally controlled PPIs (Protein-Protein Interactions) within a sensory domain that senses various stimuli and alters the functional activities of downstream effectors. This study focused on the superfamily of PAS (Per-ARNT-Sim) environmental sensory domains and their roles in regulating two Ser/Thr Kinases (STKs). PAS domains achieve their regulatory control by internally binding small molecule ligands/cofactors (e.g., O₂ binding to heme …

Molecular Mechanisms Of Amyloid-Like Fibril Formation, Sharareh Jalali

Dissertations

Proteins play a critical role in living systems by performing most of the functions inside cells. The latter is determined by the protein's three-dimensional structure when it is folded in its native state. However, under pathological conditions, proteins can misfold and aggregate, accounting for the formation of highly ordered insoluble assemblies known as amyloid fibrils. These assemblies are associated with diseases like Parkinson's and Alzheimer's. Strong evidence suggests that three mechanisms are critical for forming amyloid fibrils. These mechanisms are the nucleation of amyloid fibrils in solution (primary nucleation) as well as on the surface of existing fibrils (secondary nucleation) …

Exploring Topological Phonons In Different Length Scales: Microtubules And Acoustic Metamaterials, Ssu-Ying Chen

Dissertations

The topological concepts of electronic states have been extended to phononic systems, leading to the prediction of topological phonons in a variety of materials. These phonons play a crucial role in determining material properties such as thermal conductivity, thermoelectricity, superconductivity, and specific heat. The objective of this dissertation is to investigate the role of topological phonons at different length scales.

Firstly, the acoustic resonator properties of tubulin proteins, which form microtubules, will be explored The microtubule has been proposed as an analog of a topological phononic insulator due to its unique properties. One key characteristic of topological materials is the …