Biochemistry Commons^™

Amyloid Fibrils Of Human Fgf-1 Induced By Different Detergents, Zeina Ismael Ibrahem Alraawi

Graduate Theses and Dissertations

Nature achieves molecular self-assembly through the ordered growth of nanoscale building blocks with high efficiency to fabricate macromolecular architectures. One example of self- assembly is peptides folding onto protein is one of the most astounding biological self-assembly processes. When proteins aggregate to form amyloid fibers, the secondary structure of the protein converts from its native state to a cross-beta-sheet. Fibroblast growth factors (FGFs) possess an essential role in neuronal survival during development. In addition, they are involved in neural stem cell (NSC) proliferation. Fibroblast growth factors (FGFs) are well known to be synthesized in the central nervous system (CNS) and …

Characterization Of Human Fibroblast Growth Factor 2 Variant To Determine Effects On Structure, Stability, And Cell Proliferation, Ryan Layes

Graduate Theses and Dissertations

Fibroblast growth factors (FGFs) are a family of cell signaling proteins conserved across multiple species. Each individual FGF elicits different cellular functions including, but not limited to, proliferation, migration, differentiation, angiogenesis, and wound healing. One of the most studied members, fibroblast growth factor 2 (FGF2), has demonstrated substantial wound healing capacity in a wide range of tissues including skeletal, muscular, neural, respiratory, epithelial, and cardiovascular. This ability makes FGF2 a potential therapeutic for a wide range of conditions and injuries. However, due to a short half-life at room temperature, therapeutic use of FGF2 is limited. It has been demonstrated that …

Characterization Of The Influence Of A Small Molecule Inhibitor On Ras-Related Proteins Interactions, Emilio Duverna

Graduate Theses and Dissertations

The Ras superfamily of small G proteins are involved in cell-signaling processes that, if not regulated, may lead to cell multiplication, apoptosis inhibition, and tumorigenesis. They function as molecular switches, which through GTP/GDP exchange cycle, switch on or off cellular activities. Overexpression and/or hyperactivity of these proteins have been linked to many diseases including various cancers. CDC42, a member of the Rho subfamily of the Ras superfamily of small G proteins, participates in the regulation of many cellular processes including cell adhesion, mitosis, and cytoskeletal rearrangements. CDC42 binds to and activates many effector proteins including CDC42-activated kinase (ACK). Abnormal activities …

Preparation Of Proteins And Peptides From Heat-Stabilized Defatted Rice Bran Via Solid State Fermentation And Investigating For Skin Health, Ali A. Bisly

Graduate Theses and Dissertations

Heat-stabilized defatted rice bran (HDRB) is an abundant and inexpensive agro-industrial by-product of rice milling and rice oil extraction process. Furthermore, HDRB is a potential source of proteins. However, the direct protein extraction has low yield of protein due to the impact of heat stabilization and oil extraction process which made the HDRB proteins bound and interact with other components. This research is based on using solid-state fermentation (SSF), which is a natural and cost-effective approach to facilitate protein extraction from HDRB using Bacillus subtilis (natto) Takahashi as a microorganism.

Response surface methodology (RSM) analysis was used with Box-Behnken design …

Engineering Fluorescently Labeled Human Fibroblast Growth Factor One Mutants And Characterizing Their Photophysics Properties Towards Designing Fret Assays, Mamello Mohale

Graduate Theses and Dissertations

Human fibroblast growth factor one (hFGF1) belongs to a family of 22 FGF members produced by fibroblast cells. Cell signaling during physiological processes of angiogenesis and wound healing occurs when hFGF1 binds to its receptor (FGFR). However, when heterogenous homeostasis is not maintained, fibroblast cells exhibit excessive proliferation which can lead to a myriad of cancers. smFRET is an ultrasensitive distant dependent (1-10 nm) technique capable of resolving such heterogeneity in structural dynamics and binding affinities (Kd). Therefore, we successfully designed and characterized fluorescently labeled hFGF1 tracers which span the visible light region of the electromagnetic spectrum for use in …

Investigating Effects Of Microenvironmental Stress On Cell Metabolism Using Multiphoton Imaging, Lisa Rebello

Graduate Theses and Dissertations

Resistance to therapy in cancer is a major cause of poor prognosis in patients. Tumor hypoxia plays an active role in mediating treatment resistance and has been linked to metastases and metastatic potential in cancer. Our research focused on three objectives: i) To understand metabolic effects of chronic and intermittent hypoxia in murine breast cancer cells and its affiliation with metastatic potential ii) To identify the metabolic changes associated with radiation therapy in a panel of radiosensitive and radioresistant human head and neck cancer cells and iii) to monitor the changes in cell metabolism associated with gain of treatment resistance. …

Evaluating Bioenergetics And Mitochondrial Dynamics In Patient Fibroblasts With Pathogenic Mitochondrial Dna Mutations Causing Leigh Syndrome, Ajibola Bakare

Graduate Theses and Dissertations

Leigh syndrome (LS) is a rare fatal mitochondrial disorder of infants caused by pathogenic mutations in the nuclear (nDNA) or mitochondrial DNA (mtDNA) leading to mitochondrial dysfunction. The extent to which pathogenic mtDNA variants regulate disease severity in LS is not well understood. The heterogeneous nature of this disorder, based in part by complex mitochondrial genetics, and the nuclear and mitochondrial cross-talk has made it particularly challenging to investigate and develop therapies for treating LS . While the prognosis is poor, several studies are underway to understand the pathophysiology of LS. This dissertation provides a comprehensive structural and functional analysis …

The Biochemical Characterization Of Aza197 And A Ras Related Protein Cdc42, Alix Montoya-Beltran

Graduate Theses and Dissertations

Eukaryotic cells contain an extensive amount of GTP/GDP binding proteins. Proteins known as Ras GTPase primary function as a binary switch, where they cycle from an on and off state when GTP or GDP are bound, respectively. They are known to play a critical role in many cellular functions where a dysregulation could potentially lead to oncogenic behavior or other malignancies. In our laboratory, our focus is the study of a Ras related protein Cell division control 42 homolog (Cdc42) which belongs to the Rho subfamily. Cdc42 plays a critical role in many biological signaling processes; therefore, its uncontrol gene …

Cloning, Expression, Purification And Characterization Of Heparin-Binding Pocket Of Recombinant Fgf1, Quratulayn Ashraf

Graduate Theses and Dissertations

Fibroblast growth factors are polypeptide members of the FGF family, which to date comprises of at least 22 members. They belong to a group of growth factors and are involved in a variety of cellular processes including wound healing, angiogenesis, differentiation and development (organogenesis). Amongst FGF members, human acidic FGF-1 and basic FGF-2 are the most characterized. FGF-1 and FGF-2 are known to share more than 80% sequence similarity and have an identical structural fold. However, their biological roles are quite different. FGFs bind to heparin and heparan sulfate ligands through their heparin-binding pockets. The interactions are primarily electrostatic in …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …

Targeting Sec61Α By Ipomoeassin F Leads To Highly Cytotoxic Effect, Zhijian Hu

Graduate Theses and Dissertations

Ipomoeassin F is a flagship congener of a resin glycoside family that inhibits growth of many tumor cell lines with only single-digital nanomolar IC50 values. However, biological and pharmacological mechanisms of ipomoeassin F have been undefined. To facilitate exploration of the biological and pharmacological properties, we performed sophisticate SAR (Structure–activity relationship) studies of ipomoeassin F to understand its pharmacophore and structure properties so that we can design favorable probes for further biological investigation. By applying appropriate deviates that possess fluorescent groups and similar bio-activity, the target protein was found to be localized in endoplasmic reticulum (ER). Through biotin affinity pull …

Characterization Of A Variant Of Tuberous Sclerosis Complex 2 And Its Interaction With Rheb, Sowmya Sivakumar

Graduate Theses and Dissertations

Protein-protein interactions are vital in maintaining proper function and homeostasis in cells. Some signaling pathways are regulated by G-proteins that work like switches to activate and deactivate pathways. Mutations in these proteins, their effectors or the interaction between proteins may cause dysregulation of signals that can lead to many diseases.

Rheb, Ras homology enriched in brain, is a Ras family GTPase that is vital in regulation of the mTOR (mammalian target of rapamycin) pathway that signals cell proliferation and growth. Due to the low intrinsic GTPase activity of Rheb, a GTPase activating protein (GAP), Tuberous Sclerosis Complex 2 (TSC2) down …

Determination Of The Effects Of Different Maillard Reaction Products On The Taxonomic Composition Of The Gut Microbiota, Nesreen Hamdan Aljahdali

Graduate Theses and Dissertations

The Maillard Reaction (MR) is a non-enzymatic chemical reaction which results in linkage between the amino group of amino acids and the carbonyl group of reduced sugars. This reaction generates Maillard reaction products (MRPs) which are not present naturally in foods, and are responsible for a range of colors, odors, flavors, and other sensory properties. Conflicting reports of MRPs impacts on human health are probably due to the fact that bioconversion of these digestible molecules by the gut microbiota has been marginally taken into account. This study aimed to determine the effects of different MRPs on rodent’s gut microbiota through16S …

The Structural And Functional Properties Of A Double Mutant Of Human Acidic Fibroblast Growth Factor (Hfgf-1), Arwa Mohammed Alghanmi

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1), a member of the FGF superfamily, is a potent mitogen and heparin-binding protein involved in a broad spectrum of biological processes, including angiogenesis, cell proliferation, and wound healing. Design of hFGF-1 with an increased thermal stability and an enhanced cell proliferation activity is highly desired for wound healing applications. Herein, we have designed the variant of FGF-1 by substituting two important amino residues in the heparin-binding pocket. The variant was overexpressed in Escherichia coli and was successfully purified to homogeneity using an affinity chromatographic procedure. Far-UV circular dichroism spectroscopic analysis showed that the …

Molecular And Biochemical Studies Of Several Novel Estrogen Receptor Alpha-Interacting Proteins In Breast Cancer Cells, Ahmed Edan Dhamad

Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related death in women, and approximately 70% of incidences are estrogen receptor (ER)-positive breast cancer. ERα and its interacting proteins play a key role in the development and progression of breast cancer. However, how ERα regulates its target gene expression and hence cell proliferation is not fully understood. To enhance our understanding of the molecular mechanism by which ERα regulates gene expression, we used a quantitative proteomic method to identify cellular proteins that interact with ERα. The first group of proteins that were identified to associate with ERα are heat shock proteins …

Engineered Human Acidic Fibroblast Growth Factor (Fgf1) With An Enhanced Thermal And Proteolytic Stability, Duaa Abdullah Almansaf

Graduate Theses and Dissertations

Fibroblast growth factor receptor (FGFR) is made up of three significant domains. The most important domain is the intracellular domain where the dimerization and autophosphorylation occur. Fibroblast growth factor (FGF) interacts with specific FGFR to regulate many cellular processes during the embryonic stage. Furthermore, FGF is significant for adults because FGF plays an important role in regulating cellular differentiation as well as wound healing. The cellular regulating processes are initiated through binding FGF to heparin followed by binding FGF/heparin to FGFR to form FGF/heparin/FGFR complex. Thus, FGFR is dimerized and autophosphorylated. The phosphorylation of FGFR triggers downstream signaling pathways, which …

Influence Of Ph And Acidic Side Chain Charges On The Behavior Of Designed Model Peptides In Lipid Bilayer Membranes, Venkatesan Rajagopalan

Graduate Theses and Dissertations

The molecular properties of transmembrane proteins and their interactions with lipids regulate biological function. Of particular interest are interfacial aromatic residues and charged residues in the core helix whose functions range from stabilizing the native structure to regulating ion channels. This dissertation addresses the pH dependence and influence of potentially negatively charged tyrosine, glutamic acid or aspartic acid side chains. We have employed GWALP23 (acetyl-GGALW5LALALALALALALW19LAGA-amide) as favorable host peptide framework. We have substituted W5 with Tyr (Y5GWALP23) and Leu residues with Glu (L12E, L14E or L16E) or Asp (L14D or L16D), and have incorporated specific 2H-labeled alanine residues within the …

Local Modulation And Measurement Of Macrophage-Derived Bioactive Proteins From Implanted Biomaterials In Rat, Geetika Bajpai

Graduate Theses and Dissertations

Fibrosis around the implanted medical devices is a severe problem that can plague long-term device reliability. Activation of macrophage phenotype (macrophage polarization) has emerged as a new and possible means for reducing fibrosis in the fields of biomaterials and regenerative medicine. Macrophages are phagocytic cells that respond to microenvironmental cues that direct their phenotype. Macrophage activation has been widely studied in mouse and human in the context of tumor biology, yet little information is available regarding how macrophage activation could be used in a biomaterials context. Further, rats rather than mice are the common subjects in biomaterials experiments. A significant …

Inducing And Characterizing M2c Macrophages At A Non-Degradable Implant In Vivo, Geoffrey David Keeler

Graduate Theses and Dissertations

The implantation of biomaterials in the body leads to a reaction known as the foreign body response (FBR) which leads to the eventual encapsulation of the biomaterial. This encapsulation proves to be detrimental to certain biomaterials, such as implanted glucose sensors, which rely on interacting with the extracellular space for proper function. Altering the FBR has become of interest in an effort to increase the longevity and integration of biomaterials. One strategy for altering the FBR is by targeting the macrophage, shown to play an important role in the FBR. In this work, the microdialysis sampling technique was used to …

An Analysis Of The Redox Properties And Stability Of Chlamydomonas Reinhardtii Cytochrome F, Cytochrome C6, And Mutants Thereof, Nicole Lynn Vanderbush

Graduate Theses and Dissertations

This body of work presents mutagenesis studies conducted on two c-type cytochromes from Chlamydomonas reinhardtii. Cytochrome f, a unique c-type cytochrome, is investigated in regards to its redox potential, the dependence of the redox potential, and the thermal stability of the protein. The mutations made were Y1F, Y9F, Y160F, Y160L, R156L, and R156K. The residues that were mutated surround the heme. It was found that, relative to the wild-type, only the Y160L and R156 mutants showed any difference in midpoint potential at pH 7. Wild-type and mutants both had a midpoint potential that was dependent upon pH indicating that none …

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan

Graduate Theses and Dissertations

Oligopeptides and low molecular weight polypeptides play central roles as effectors and signal transducers acting as hormones, neurotransmitters, growth factors, toxins, and antimicrobial factors that are important for the survival of the organism. Owing to the ubiquitous involvement of peptides in many key regulatory processes, we have been interested to identify native peptides in different cells and tissues and understand their functions. To conduct our studies, we used avian macrophages and heterophils as models of specialized cells which constitute central components of innate immunity. These studies involved (a) qualitative identification and characterization of the peptides associated with high intensity mass …