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Full-Text Articles in Biomedical Engineering and Bioengineering

Biomarker Detection At Risk Forecasting Level Using Metal-Enhanced Fluorescence Combined With Surface Acoustic Wave, Jun Liu Nov 2016

Biomarker Detection At Risk Forecasting Level Using Metal-Enhanced Fluorescence Combined With Surface Acoustic Wave, Jun Liu

Graduate Theses and Dissertations

In this paper, metal-enhanced fluorescence (MEF) technique is used to lower the detection limit of carcinoembryonic antigen (CEA) which is able to be utilized in forecasting the risk of having certain kinds of cancers, especially colon and rectal cancer. By incubating silver nanocubes (Ag NCs) on the surface of the chips, the detection limit goes down to below 1ng/mL of CEA. Also, when combining MEF with surface acoustic wave (SAW) devices, the incubation time between antigen and antibody will decrease significantly with the fluorescence signal keeping similar or higher level.


Nano-Photonic Waveguides For Chemical And Biomedical Sensing, Surya Venkatasekhar Cheemalapati May 2016

Nano-Photonic Waveguides For Chemical And Biomedical Sensing, Surya Venkatasekhar Cheemalapati

Graduate Theses and Dissertations

In this dissertation, advances in the fields of Photonics, and Plasmonics, and specifically, single cell analysis and waveguide sensing will be addressed. The first part of the dissertation is on Finite Difference Time Domain (FDTD) optimization and experimental demonstration of a nano-scale instrument that allows sensing at the cellular and subcellular levels. A new design of plasmonic coupler into a nanoscale waveguide is proposed and optimized using FDTD simulations. Following this, a subcellular nanoendoscope that can locally excite fluorescence in labelled cell organelles and collect the emitted fluorescent light for detailed spectrum analysis is fabricated and tested. The nanoendoscope has ...


Silicone Elastomer-Based Combinatorial Biomaterial Gradients For High Throughput Screening Of Cell-Substrate Interactions, Greeshma Mohan Jan 2015

Silicone Elastomer-Based Combinatorial Biomaterial Gradients For High Throughput Screening Of Cell-Substrate Interactions, Greeshma Mohan

Graduate Theses and Dissertations

Biomaterials have evolved over the years from the passive role of mere biocompatibility to an increasingly active role of presenting instructive cues to elicit precise responses at the molecular and cellular levels. Various characteristics common to synthetic biomaterials in vitro and extracellular matrices in vivo, such as immobilized functional or peptide groups, mechanical stiffness, bulk physical properties and topographical features, are key players that regulate cell response. The dynamics in the cell microenvironment and at the cell adhesive interface trigger a web of cell-material and cell-cell information exchanges that have a profound impact in directing the ultimate cell fate decision ...


Fabrication Of Tissue Precursors Induced By Shape-Changing Hydrogels, Olukemi O. Akintewe Jan 2015

Fabrication Of Tissue Precursors Induced By Shape-Changing Hydrogels, Olukemi O. Akintewe

Graduate Theses and Dissertations

Scaffold based tissue reconstruction inherently limits regenerative capacity due to inflammatory response and limited cell migration. In contrast, scaffold-free methods promise formation of functional tissues with both reduced adverse host reactions and enhanced integration. Cell-sheet engineering is a well-known bottom-up tissue engineering approach that allows the release of intact cell sheet from a temperature responsive polymer such as poly-N-isopropylacrylamide (pNIPAAm). pNIPAAm is an ideal template for culturing cell sheets because it undergoes a sharp volume-phase transition owing to the hydrophilic and hydrophobic interaction around its lower critical solution temperature (LCST) of 32°C, a temperature close to physiological temperature. Compared ...


Structured Materials For Catalytic And Sensing Applications, Selma Hokenek Jan 2013

Structured Materials For Catalytic And Sensing Applications, Selma Hokenek

Graduate Theses and Dissertations

The optical and chemical properties of the materials used in catalytic and sensing applications directly determine the characteristics of the resultant catalyst or sensor. It is well known that a catalyst needs to have high activity, selectivity, and stability to be viable in an industrial setting. The hydrogenation activity of palladium catalysts is known to be excellent, but the industrial applications are limited by the cost of obtaining catalyst in amounts large enough to make their use economical. As a result, alloying palladium with a cheaper, more widely available metal while maintaining the high catalytic activity seen in monometallic catalysts ...


Shape-Shifting Surfaces For Rapid Release And Direct Stamping Of Organized Micro-Tissues, Samuel James Dupont Jan 2012

Shape-Shifting Surfaces For Rapid Release And Direct Stamping Of Organized Micro-Tissues, Samuel James Dupont

Graduate Theses and Dissertations

The primary aim of the research in this study is to develop a robust and simple platform for the in vitro organization of cells on surfaces which facilitate rapid cell release and allows for the direct stamping of highly organized micro-tissues. Current approaches towards this goal have been very successful but are lengthy and subject cells to harsh conditions for extended periods of time raising questions regarding cell health and maintenance of physiological state. To address these concerns a platform was developed to allow for rapid cell release by utilizing a release mechanism different from previous work.

Micron-scale structures comprised ...


High Throughput Design Of Functionalized Nanoparticles For Targeted Vaccine Delivery, Ana Vianey Chavez-Santoscoy Jan 2011

High Throughput Design Of Functionalized Nanoparticles For Targeted Vaccine Delivery, Ana Vianey Chavez-Santoscoy

Graduate Theses and Dissertations

This dissertation focuses on the design of functionalized nanoparticles, a novel approach to targeted antigen delivery by decorating the surface of polyanhydride nanoparticles with specific carbohydrates to provide "pathogen-like" properties.

Polyanhydride nanoparticles are promising vaccine platforms that have the potential to be used as controlled drug delivery devices as well as potent and effective immune adjuvants for the design of single dose vaccines. CLRs offer unique advantages for tailoring immune responses. Engagement of CLRs regulates antigen presenting cell activation and promotes delivery of antigens to specific intracellular compartments inside antigen presenting cells for efficient processing and presentation.

CLRs recognize conserved ...


Functional Materials From Hierarchically Ordered Polymer Nanocomposites, Brandon Josef Franck Jan 2011

Functional Materials From Hierarchically Ordered Polymer Nanocomposites, Brandon Josef Franck

Graduate Theses and Dissertations

We report work done studying the segregation of polymer coated gold nanoparticles within block copolymer (BCP) composites. Poly(styrene-b-isoprene) (PI-b-PS) of Mn 172 kDa was loaded with various particle fractions of gold nanoparticle with various surface chemistries. Segregation of the particles within the BCP composite was examined via electron microscopy. "Single component" nanocomposites with BCP ligands of PI-b-PS and poly(isoprene-b-dimethylsiloxane) "grafted to" gold nanoparticles were introduced and a study of ordering was done via electron microscopy and small-angle x-ray scattering.


Multiscale Modeling For Complex Macromolecular Systems: Methodologies And Applications, Seung Ha Kim Jan 2011

Multiscale Modeling For Complex Macromolecular Systems: Methodologies And Applications, Seung Ha Kim

Graduate Theses and Dissertations

The objective of this dissertation is to understand the binding mechanism between flexible macromolecules and guest species in solution using multiscale molecular modeling strategies, including: ab initio electronic structure theory, all-atom classical molecular dynamics simulations, coarse-grained molecular dynamics simulations, and statistical eld theory. A brief summary of the subsequent chapters in this thesis is provided. Chapters 2 - 7 and Appendix A are self-contained units complete with literature review and bibliography.


Self-Assembled Pentablock Copolymers For Selective And Sustained Gene Delivery, Bingqi Zhang Jan 2011

Self-Assembled Pentablock Copolymers For Selective And Sustained Gene Delivery, Bingqi Zhang

Graduate Theses and Dissertations

The poly(diethylaminoethyl methacrylate) (PDEAEM) - Pluronic F127 - PDEAEM pentablock copolymer (PB) gene delivery vector system has been found to possess an inherent selectivity in transfecting cancer cells over non-cancer cells in vitro, without attaching any targeting ligands. In order to understand the mechanism of this selective transfection, three possible intracellular barriers to transfection were investigated in both cancer and non-cancer cells. We concluded that escape from the endocytic pathway served as the primary intracellular barrier for PB-mediated transfection. Most likely, PB vectors were entrapped and rendered non-functional in acidic lysosomes of non-cancer cells, but survived in less acidic lysosomes of ...


Surface Functionalization Of Quantum Dots For Biotechnological Applications, Yanjie Zhang Jan 2011

Surface Functionalization Of Quantum Dots For Biotechnological Applications, Yanjie Zhang

Graduate Theses and Dissertations

Quantum dots (QDs) are considered as fantastic substitutes for organic dyes or genetically coded proteins because of their outstanding optical properties including broad absorption spectra, size tunable emission spectra, large extinction coefficient and superior resistance to chemical and physical degradation. They are now widely used in many biological applications. However, QDs are generally synthesized using organometallic approach and only soluble in organic solvents. To transfer QDs into aqueous solution, we replaced their native ligands with a new group of water-soluble molecules based on simple yet flexible dithiocarbamate chemistry. This cap exchange method offers QDs not only solubility but also stability ...


Engineering Amphiphillic Polyanhydride Particle Platform For Targeted Drug And Vaccine Delivery, Brenda Rocio Carrillo-Conde Jan 2011

Engineering Amphiphillic Polyanhydride Particle Platform For Targeted Drug And Vaccine Delivery, Brenda Rocio Carrillo-Conde

Graduate Theses and Dissertations

In this work, a transdisciplinary approach that combines concepts from biomaterials, nanotechnology, carbohydrate and protein chemistry, molecular biology, immunology and computational analysis has been applied to rationally design and engineer novel vaccine platforms that encompass passive and active targeting strategies.

First, the intrinsic properties of the polyanhydride systems utilized in these studies were tailored to achieve the stability of proteins with the potential to be used as antigens and/or therapeutic agents. Amphiphillic polyanhydride chemistries showed the most optimal properties to preserve structural integrity and functionality of different proteins. The surface chemistry of polyanhydride particles was also identified as an ...


Purification Of Flavan-3-Ol Biosynthesis For Co-Localization Onto Nanocarriers And A Multi-Enzyme Assay, Emily Kaitlin Davenport Jan 2011

Purification Of Flavan-3-Ol Biosynthesis For Co-Localization Onto Nanocarriers And A Multi-Enzyme Assay, Emily Kaitlin Davenport

Graduate Theses and Dissertations

Flavonoids are polyphenolic secondary metabolites that serve a variety of purposes, from assisting pollination in plants to providing anti-cancerous activity in humans. It is the wide range of functions that give these molecules the highly revered status they have today. Range in function can be linked with the range in structure, and with over 10,000 different flavonoids known, they make up one of the largest groups of natural products. One common sub-class of flavonoids is the flavan-3-ols, which are known for their health benefits and tendency to condense to form proanthocyanidins, or condensed tannins. Both of these classes of ...


Multiple Disturbance Modeling And Prediction Of Blood Glucose In Type 1 Diabetes Mellitus, Kaylee Renee Kotz Jan 2011

Multiple Disturbance Modeling And Prediction Of Blood Glucose In Type 1 Diabetes Mellitus, Kaylee Renee Kotz

Graduate Theses and Dissertations

Type 1 diabetics often experience extreme variations in glucose concentrations which can have adverse long– and short–term effects such as severe hypoglycemia, hyperglycemia and organ degeneration. Studies have established that there is a need to maintain the glucose levels within a normal range (e.g. 80—150 mg/dL) to avoid complications caused by diabetes. However, initial attempts to regulate blood glucose levels using insulin infusion pumps, multiple injections or a combination of the two have had limited success as they lack the ability to decide the appropriate rate and/or dose of insulin based on the current metabolic ...


Modeling Of Complex Surface Interactions In Low And High Pressure Plasmas, Mingmei Wang Jan 2011

Modeling Of Complex Surface Interactions In Low And High Pressure Plasmas, Mingmei Wang

Graduate Theses and Dissertations

Plasma etching (or dry etching) is widely used in the fabrication of integrated cir-cuits (IC). Anisotropic features are easily obtained by controlling reactive ion trajectories in plasma. Twisting and bowing are two main issues during high aspect ratio (HAR) fea-ture etching. Twisting is, instead of a feature etching vertically, the feature twists or turns to the side. Mixing damage by ion bombardment of underlying materials is also a critical problem in post-etch processing. One of the explanations for twisting is charge accumu-lation on feature surfaces during ion bombardment. An asymmetric local electric field (E-field) changes ion trajectories incident into the ...


Steam Reforming Of Water-Soluble Fast Pyrolysis Bio-Oil: Studies On Bio-Oil Composition Effect, Carbon Deposition, And Catalyst Modifications, Pedro J. Ortiz-Toral Jan 2011

Steam Reforming Of Water-Soluble Fast Pyrolysis Bio-Oil: Studies On Bio-Oil Composition Effect, Carbon Deposition, And Catalyst Modifications, Pedro J. Ortiz-Toral

Graduate Theses and Dissertations

Bio-oils from fast pyrolysis of lignocellulosic biomass can be phase separated into a heavy water insoluble portion and a light water-soluble portion. The water-rich portion contains mainly carboxylic acids, carbohydrates, aldehydes, ketones and alcohols. This highly oxygenated water-rich portion was evaluated for production of the renewable hydrogen required for the upgrading reactions. There are certain challenges introduced due to the complexity of these mixtures. Catalyst deactivation by coking and the formation of carbon deposits are major limitations although the specific causes were previously unidentified. A bio-oil fractionating system can separate heavier components from the light-end components. This light-end fraction has ...


Combinatorial Design And Development Of Biomaterials For Use As Drug Delivery Devices And Immune Adjuvants, Latrisha Kay Petersen Jan 2011

Combinatorial Design And Development Of Biomaterials For Use As Drug Delivery Devices And Immune Adjuvants, Latrisha Kay Petersen

Graduate Theses and Dissertations

There are several challenges associated with current strategies for drug and vaccine delivery. These include the need for multiple-dose administrations, which can hinder patience compliance, the requirements for specific storage conditions due to the fragile structure of protein-based molecules, and the need for additional excipients to enhance protein stability or adjuvant the immune response. This work has focused on the development of a high throughput, combinatorial approach to optimize degradable polymeric biomaterials, specifically polyanhydrides, to overcome these challenges associated with drug and vaccine delivery. We have developed high throughput techniques to rapidly fabricate polymer film and nanoparticle libraries to carry ...


Use Of Colloidal Crystal Templating To Fabricate Ordered Pit Arrays On Aluminum And Aluminum Alloy 3003, Newira Widharta Jan 2011

Use Of Colloidal Crystal Templating To Fabricate Ordered Pit Arrays On Aluminum And Aluminum Alloy 3003, Newira Widharta

Graduate Theses and Dissertations

In a number of industrial processes, metal surfaces are etched to develop topographic patterns consisting of microscopic cavities. Al alloy plates for lithographic printing are etched to create a microscopically roughened surface that optimizes retention of ink and release agent. Fabrication of ordered arrays of micro-porous pits utilizing colloidal crystal templating method in aluminum and aluminum alloy 3003 was developed in this thesis. We choose such a technique, previously developed for aluminum electrolytic capacitors, and adapt it to aluminum alloy 3003 substrates used in the solid-ink lithography. Using electrochemistry and imaging techniques (SEM), we showed that ordered pit arrays with ...


Metabolic Flux Analysis Of Escherichia Coli Mg1655 Under Octanoic Acid (C8) Stress, Yanfen Fu Jan 2011

Metabolic Flux Analysis Of Escherichia Coli Mg1655 Under Octanoic Acid (C8) Stress, Yanfen Fu

Graduate Theses and Dissertations

Metabolic engineering has evolved to the point of fulfilling the dream of having industrial chemicals produced renewably. Carboxylic acids [e.g., short chain fatty acids (SCFAs) such as octanoic acid (C8)] are such chemical intermediates that can be produced by Escherichia coli engineered with thioesterases specific for short chain fatty acids. However, C8 is toxic to E. coli at concentration greater than 10 mM. To design a better host strain for the production of large amount of SCFAs, 13C metabolic flux analysis of E. coli was performed for both C8 stress and control condition (without C8). To investigate central carbon ...


The Conversion Of Low-Grade Heat Into Power Using Supercritical Rankine Cycles, Huijuan Chen Nov 2010

The Conversion Of Low-Grade Heat Into Power Using Supercritical Rankine Cycles, Huijuan Chen

Graduate Theses and Dissertations

Low-grade heat sources, here defined as below 300 ºC, are abundantly available as industrial waste heat, solar thermal, and geothermal, to name a few. However, they are under-exploited for conversion to power because of the low efficiency of conversion. The utilization of low-grade heat is advantageous for many reasons. Technologies that allow the efficient conversion of low-grade heat into mechanical or electrical power are very important to develop.

This work investigates the potential of supercritical Rankine cycles in the conversion of low-grade heat into power. The performance of supercritical Rankine cycles is studied using ChemCAD linked with customized excel macros ...


Plasma Mediated Molecular Delivery, Richard J. Connolly Oct 2010

Plasma Mediated Molecular Delivery, Richard J. Connolly

Graduate Theses and Dissertations

Non-viral delivery of plasmid DNA has traditionally relied upon physical forces applied directly to target tissues. These physical methods typically involve contact between an applicator and the target tissue and often cause transient patient discomfort. To overcome the contact-dependent limitations of such delivery methodologies, an atmospheric direct current plasma source was developed to deposit ionized gas molecules onto localized treatment sites. The deposition of charged species onto a treatment site can lead to the establishment of an electric field with strengths similar to those used for traditional electroporation. In vitro experiments proved that this technology could transiently permeabilize cell membranes ...


The Virtual Hip: An Anatomically Accurate Finite Element Model Based On The Visible Human Dataset, Jonathan M. Ford Oct 2010

The Virtual Hip: An Anatomically Accurate Finite Element Model Based On The Visible Human Dataset, Jonathan M. Ford

Graduate Theses and Dissertations

The purpose of this study is to determine if element decimation of a 3-D anatomical model affects the results of Finite Element Analysis (FEA). FEA has been increasingly applied to the biological and medical sciences. In order for an anatomical model to successfully run in FEA, the 3-D model’s complex geometry must be simplified, resulting in a loss of anatomical detail. The process of decimation reduces the number of elements within the structure and creates a simpler approximation of the model. Using the National Library of Medicine’s Visible Human Male dataset, a virtual 3-D representation of several structures ...


Investigation Of Buildup Dose For Therapeutic Intensity Modulated Photon Beams In Radiation Therapy, Khosrow Javedan Jul 2010

Investigation Of Buildup Dose For Therapeutic Intensity Modulated Photon Beams In Radiation Therapy, Khosrow Javedan

Graduate Theses and Dissertations

Buildup dose of Mega Voltage (MV) photon beams can be a limiting factor in intensitymodulated radiation therapy (IMRT) treatments. Excessive doses can cause patient discomfort and treatment interruptions, while underdosing may lead to local failure.

Many factors which contribute to buildup dose, including the photon beam energy spectrum, scattered or contaminant radiation and their angular distribution, are not modeled well in commercial treatment planning systems. The accurate Monte Carlo method was employed in the studies to estimate the doses.

Buildup dose of 6MV photon beams was investigated for three fundamentally different IMRT modalities: between Helical TomoTherapy and traditional opposed tangential ...


Synthesis, Characterization, And Self-Assembly Of Gold Nanorods And Nanoprisms, Kristina L. Tran Jun 2010

Synthesis, Characterization, And Self-Assembly Of Gold Nanorods And Nanoprisms, Kristina L. Tran

Graduate Theses and Dissertations

The unique properties of gold nanoparticles make them excellent candidates for applications in electronics, sensing, imaging, and photothermal therapy. Though abundant literature exists for isotropic gold nanoparticles, work on nanoparticles of different shapes has been gaining interest recently. Anisotropic gold nanoparticles, such as nanorods and nanoprisms, have tunable optical properties in the visible and near-infrared regions. Through synthesis and surface modification, the production of various shapes of these gold nanoparticles can be controlled to meet different applications.

Two different types of gold nanorods were used in this thesis. The first type was stabilized with cetyltrimethylammonium bromide (CTAB) and had aspect ...


Effects Of Monoclonal Anti-Abeta Antibodies On The Amyloid Beta Peptide Fibrillogenesis And Their Involvement In The Clearance Of Alzheimer's Disease Plaques, Jeffy Pilar Jimenez May 2010

Effects Of Monoclonal Anti-Abeta Antibodies On The Amyloid Beta Peptide Fibrillogenesis And Their Involvement In The Clearance Of Alzheimer's Disease Plaques, Jeffy Pilar Jimenez

Graduate Theses and Dissertations

Alzheimer’s disease (AD) is the most common cause of senile dementia worldwide. AD is a neurodegenerative disorder characterized by the loss of memory and language skill, collapse of the cognitive function, and distortion of social behavior. As of today, the onset mechanisms of AD and cure are unknown; however, three hallmarks are commonly encountered: extra and intracellular accumulation of amyloid beta (A!) peptide plaques, formation of intracellular neurofibrillary tangles, and inevitable neuronal death. Hypothetically, a possible scenario provoking or involved in the onset of AD is a cascade effect that starts with an imbalance in the production and clearance ...


Catalytic Strategies Of Glycoside Hydrolases, Luis Petersen Jan 2010

Catalytic Strategies Of Glycoside Hydrolases, Luis Petersen

Graduate Theses and Dissertations

Glycoside hydrolases (GHs) are enzymes that catalyze the hydrolysis of the glycosidic bond between two carbohydrate residues or a carbohydrate unit linked to a non-carbohydrate aglycon unit. Despite years of research dedicated to GHs, there are still several mechanistic details, relevant for individual GH enzymes, that remain to be investigated. In this work, a computational analysis of the detailed mechanism of several GHs is presented. QM/MM metadynamics simulations of two glycoside hydrolases, GH8 endoglucanase and GH43 β-xylosidase, give insight into the enzymatic deconstruction of the plant cell wall, and the detailed reaction mechanism of both enzymes. In addition, an ...


Alternative Routes For Purification Of Collagen Type I Α1 From A Whole Corn Extract, Christopher Michael Setina Jan 2010

Alternative Routes For Purification Of Collagen Type I Α1 From A Whole Corn Extract, Christopher Michael Setina

Graduate Theses and Dissertations

Transgenic corn is capable of producing and storing Type I α1 human collagen (r-CIα1) containing a sequence that assists assembly (foldon) and the mature cleaved form (without foldon). Extracts of ground corn grain spiked with Pichia-sourced collagen (rP-CIα1), with and without foldon, were precipitated with NaCl to purify collagen from host cell proteins. The low acid solubility of host cell proteins (HCP's) along with the acid stability of collagen favored extraction at pH 2. NaCl concentrations >0.75 M provided complete precipitation of rP-CIα1 without foldon and >70% purity. A fractional cut to remove HCP's with 0 ...


Protein And Oil Recoveries From Enzyme-Assisted Aqueous Extraction Of Soybeans And Sunflower Seed, Kerry Alan Campbell Jan 2010

Protein And Oil Recoveries From Enzyme-Assisted Aqueous Extraction Of Soybeans And Sunflower Seed, Kerry Alan Campbell

Graduate Theses and Dissertations

Aqueous extraction processing (AEP) of soybeans has the potential to achieve oil extraction yields comparable to hexane extraction without the environmental or safety concerns associated with hexane. The economic viability of this novel process depends upon maximizing the yield of free oil as well the development of a cost effective, high yielding method of recovering protein values in the aqueous by-product.

In order to direct strategies for yield improvement, mechanisms of AEP were studied by microscopic observation of extracted residual solids coupled with yield measurements and mathematical modeling. The nature of the oil-confining matrix varied depending on physical treatment of ...


Development Of A Sorbent For Carbon Dioxide, Dursun Can Ozcan Jan 2010

Development Of A Sorbent For Carbon Dioxide, Dursun Can Ozcan

Graduate Theses and Dissertations

The reversible absorption of CO2 by CaO at high temperature is a promising method for capturing and removing CO2 from a hot gas stream. The main challenge facing the use of this method is the deterioration of CO2 absorption capacity when the method is applied over a large number of CO2 absorption/desorption cycles. Although various techniques have been proposed for improving the cyclic stability and performance of calcium based sorbents, a cost effective method is still needed for industrial applications. Therefore, two promising methods for improving the cyclic stability were selected for further investigation. One method is to optimize ...


Structures, Kinetics, And Modeling Of Glycoside Hydrolase Family 44 Endoglucanases From Clostridium Acetobutylicum And Ruminococcus Flavefaciens Fd-1, Christopher Donald Warner Jan 2010

Structures, Kinetics, And Modeling Of Glycoside Hydrolase Family 44 Endoglucanases From Clostridium Acetobutylicum And Ruminococcus Flavefaciens Fd-1, Christopher Donald Warner

Graduate Theses and Dissertations

Glycoside hydrolases (GH) are enzymes that hydrolyze glycosidic bonds between carbohydrates. Family 44 contains endo- and xylo- glucanases capable of hydrolyzing cellulose and hemicelluose. Two members produced by Clostridium acetobutylicum and Ruminococcus flavefaciens FD-1 are the subjects of characterization work in this dissertation.

The EG from Clostridium acetobutylicum was characterized both structurally and kinetically. Crystallization and x-ray diffraction to 2.2-y resolution revealed a TIM barrel-like structure with additional ψ-loop and β-sandwich folds. The EG hydrolyzes cellotetraose and larger cellooligosaccharides, as well as carboxymethylcellulose and xylan at approximately the same rates. It converts lichenan to oligosaccharides of intermediate size and ...