Life Sciences Commons^™

Structural Studies Of Recombinant Human Β-Casein Proteins, Yilin Hu

Loma Linda University Electronic Theses, Dissertations & Projects

β-Casein is the major component (~80%) of the human casein system. Interacting with calcium and phosphates through its phosphorylated N-terminus, β-casein participates in the formation of micelles which carry these otherwise insoluble nutrients indispensable for the growth and development of newborns. Human β-casein, or fragments thereof, are also found to have biological effects such as enhancement of calcium absorption. So far, knowledge of micelle formation is limited and structural studies of β-casein, especially its N-terminal portion will provide a better understanding of the structure-function relationship of milk micelles.

To elucidate the role that the N-terminus of the protein plays in …

A Study On The Effects Of The N-Terminal Amino Acid Sequence On The Activation Of Human T-Cell Leukemia Virus Type 1 Protease, Hidayah Muhammad Kendall

Chemistry & Biochemistry Theses & Dissertations

Human T-cell leukemia virus type 1 (HTL V-1) is dependent upon the enzymatic activity of its protease for maturation. Maturation of the protease is facilitated by cleavage of specific amino acid residues, followed by dimerization. The effects of the amino acid sequence located N-terminally to the cleavage site on the ability of the protease to become active were the focus of the current study. These amino acid sequences were contributed by the plasmid vector into which the protease gene was inserted.

Surface probability analyses (SPAs) of the vectors, as well as for native sequences which produce the mature protease and …

Regulation Of Connexin43 By Phosphorylation, Maithili M. Shah

Loma Linda University Electronic Theses, Dissertations & Projects

Gap junctions play a crucial role in embryogenesis, especially of the heart where connexin43 is thought to be important for its formation as well as synchronized contraction. Several reports have shown that connexin43 protein is phosphorylated on serine residues in vitro and in vivo.

Studies performed in our laboratory have demonstrated that cell-to-cell communication in cells expressing connexin43 can be controlled rapidly and reversibly by microinjection of active protein kinases or phosphatases that target serine or threonine residues. Phosphorylation by cAMP-dependent protein kinase (PKA) seems to favor channel opening, whereas the effect of protein kinase C (PKC) on channel gating …

Tissue-Specific Expression And Steroid Hormone Regulation Of Human Gonadotropin -Releasing Hormone (Hgnrh) Gene In Placental Cells (Jeg -3 Cells), Zhengguang Chen

Theses and Dissertations in Biomedical Sciences

Using JEG-3 cells as an in vitro model, I investigated the mechanisms behind the tissue-specific expression and steroid hormone regulation of the hGnRH gene in the human placenta. The hGnRH upstream promoter was found to be functionally active in JEG-3 cells. The DNA sequence responsible for functioning of the upstream promoter in JEG-3 cells is narrowed to a region between –1048 bp and –730 bp. This DNA fragment contains four elements, which can bind with nuclear extract from JEG-3 cells (but not from GT1-7 cells).

Estradiol (E2) represses the hGnRH upstream promoter activity in JEG-3 cells. This inhibition is receptor-mediated, …

Nitrate Reductase Activity, Nitrate Uptake And Iodine Speciation In The Marine Environment, Chin-Chang Hung

OES Theses and Dissertations

The present method for the determination of new production (NP) by measuring the uptake of added ¹⁵NO₃^– suffers from a number of limitations. In an attempt to improve this situation, this research examined the possibility of estimating ¹⁵NO₃– uptake by measuring the activity of nitrate reductase (NRA). In addition, because it has long been suspected that the biological reduction of IO₃^– to I^– may be mediated by nitrate reductase (NR), this research investigated the ability of NR to catalyze the reduction of iodate to iodide.

An improved method for the determination …

Generation Of Human Chorionic Gonadotropin Beta Subunit Specific Monoclonal Antibody Using A Synthetic Peptide, Zhe Huang

Chemistry & Biochemistry Theses & Dissertations

Human chorionic gonadotropin (hCG) is well known for early immunological and bioassay tests for early detection of pregnancy. Since the hormone specific beta subunit confers unique biological and immunological specificity to hCG, immunochemical measurement of hCG has achieved greater specificity and sensitivity in recent years by using either the beta subunit as an immunogen or a partially reduced beta subunit polypeptide chain. However, antiserum raised against the entire hCG beta subunit usually cross-reacts to some extent with human luteinizing hormone (hLH). hCG has been found to be present in the extract of tumors and minute quantities of hCG are synthesized …

Regulation Of Synthesis And Actions Of Bone Growth Factors, Rashmi Malpe

Loma Linda University Electronic Theses, Dissertations & Projects

Among the many bone growth factors, this study focused on the IGF and BMP systems because of some of their unique functions, namely, IGFs function both as local and systemic agents and BMPs are capable of inducing de novo bone formation at non-skeletal sites. There is varied osteoblast differentiation in and load bearing on the skeletal system which led to the first study whose hypothesis was that these skeletal site dependent differences are associated with site-specific differences in IGF system components' production. Results from their quantitation in the CM of normal HBC derived from calvaria, mandibles, ribs, vertebrae, and marrow …

Oligosaccharides From Cell Surface Glycoproteins Of Thermoplasma Acidophilum, An Archae, Gitanjali Srivastava

Honors Theses

No abstract provided.

Evidence That Cys230 And Lys238 Of Biotin Carboxylase Do Not Act As An Acid-Base Pair To Deprotonate Biotin, Robert Brett Lloyd

Honors Theses

No abstract provided.

Production Of Copper-Complexing Ligands In Response To Elevated Concentrations Of Copper In Marine Synechococcus Spp., Arunsri Chatkaeomorakot Brown

Theses and Dissertations in Biomedical Sciences

Synechococcus spp. (marine cyanobacteria) are extremely sensitive to copper toxicity and can produce high-affinity ligands of unknown structure which form complexes with free cupric ion. These ligands may contribute to the biological control of the levels of free cupric ions in surface seawater. Synechococcus spp. are known to produce metallothioneins (MT) in response to cadmium and zinc stress. In the present study the hypothesis that marine Synechococcus produce MT in response to copper was tested. Three marine Synechococcus spp. i.e., PCC 7001, PCC 73109, and PCC 7003, were exposed to different concentrations of CUSO 4 for various time periods. Size …

Fabrication Of Protein Arrays Using Electron Beam Lithography, Duy-Bao Phan Dinh

Theses, Dissertations and Capstones

Very few electron beam based methods for producing high-resolution patterns of surface bound proteins on glass have been developed.

There are only two types of end groups at the surface of glass, they are silanol and siloxane groups. An estersil layer can be formed on the surface of glass by treatment with hot alcohol creating a hydrophobic layer. The reaction is depicted as follows.

-Si-OH + HOR -SiO-R +H2O R = alkyl chain

The proposal that protein arrays could be fabricated by patterned electron bombardment using estersils as a negative resist was tested in this research. The hydrophobic estersil layer …

The Acquisition And Quantitative Analysis Of Digitally Generated Fourier Transforms Resulting From The Physiognomy Of Various Tree And Shrub Species, Alicia Eldridge-Spears

Theses, Dissertations and Capstones

An optical Fourier transform represents the interference of wavefronts produced as light passes through multiple slits. Theoretically, any image containing periodic structure causes diffraction. The cellular arrangement of a plant leaf and the regularity in venation are ideal conditions for diffracting light. As light passes through columns of cells, its path is altered according to the distance and orientation present.

A photograph or slide of a leaf or the leaf itself may be used to produce a diffraction pattern by either optical or digital means. Optically, a laser beam directed through a slide is refracted by a converging lens and …

Benthic Biodiversity And Physico-Chemical Parameters Of Acid Mine Drainage, Acid Impacted And Nonimpacted Streams, Stephen D. Greene

Theses, Dissertations and Capstones

South Fork of Sand Lick Creek, Logan County, West Virginia, drains an abandoned coal strip mine which had exploited Pottsville series coalbeds (Pennsylvania strata). These strata outcrop throughout southwestern West Virginia. North Fork watershed is relatively unchanged, save a small roadcut throughout. South Fork benthic community had not recovered although mining activity had ceased about 20 years earlier. Benthic communities were analyzed with detrended correspondence analysis (DCA). Family Chironomidae predominated South Fork benthic community throughout the study. North Fork’s benthic community had as major contributors acid resistant caddisfly family Hydropsychidae, mayfly family Baetidae, and stonefly families Perlodidae and Nemouridae. Family …

Clarification Of The Hybrid Origin Of Carex X Deamii Herm. (Cyperaceae) Based On Macro And Micro Morphological Characters, Paul B. Marcum

Theses, Dissertations and Capstones

The origin of Carex x deamii Herm. has been in question ever since it was named to science in 1938. Collections of the hybrid have always been associated with C. shortiana Dewey and either C. typhina Michx. or C. squarrosa L.. C. typhina and C. squarrosa are closely related taxa (Section Squarrosae) and often are morphologically similar. Because of this similarity, determining the correct parental species to the hybrid has been extremely difficult. It is known that the hybrid is sterile and only reproduces asexually. Pollen was analyzed to ascertain the viability of all four taxa. This study utilizes both …

Preparation Of N-(Haloaryl) Succinimides, Okey Noe Ii

Theses, Dissertations and Capstones

N-(3,5-Dichloro-4-fluorophenyl)succinimide (NDCFPS) and N-(3,5-dichloro-4- pyridyl)succinimide (NDPyS) were synthesized using procedures employed previously for N-(3,5-dichIorophenyl)succinimide (NDPS). However, NDPyS was not formed cleanly: extraction from by-products was necessary and purification by column chromatograpy was required. Several potential alternative routes to NDPyS were investigated without success.

Both compounds were administered to male Fischer 344 rats to assess nephrotoxic potential. NDCFPS, contrary to expectations, was non-nephrotoxic. Preliminary results indicate that NDPyS is also non-nephrotoxic.

Interaction Of Laminin Beta2 With Eps8 And Desmin In Muscle Cells, Luke Xueliang Cui

Theses, Dissertations and Capstones

Laminin β2 is localized to the synaptic basal lamina (BL) in muscle and glomerular BL in kidney. To find interacting proteins, a mouse kidney cDNA library was screened with domain I of rat laminin β2 using the yeast two-hybrid system. Fifteen positive clones were found. The DNA sequence of three each of these clones corresponded to the phosphoprotein Eps8 (epidermal growth factor receptor pathway substrate clone 8, which is tyrosine phosphorylated after EGF stimulation) and the intermediate filament (IF) protein keratin. To determine if this interaction occurred in muscle cells, C2 cells transfected with the rat …

The Role Of Retinoids And Protein Kinase C In Vascular Smooth Muscle Cell Proliferation And Function, Shaoshan Wang

Theses, Dissertations and Capstones

The structural and functional changes in the arterial wall of humans and animals accompany the development of hypertension and atherosclerosis. Hence, great interest exists in the mechanisms that govern vascular smooth muscle cell contraction and proliferation. Rat aortic rings maintained in organ culture show a significant loss of contractility; whereas, vascular smooth muscle cells in culture quickly dedifferentiate into a secretory phenotype with a marked capacity for proliferation. The addition of all-trans retinoic acid (RA) and retinol to the plasma-containing medium preserved the contractile response of cultured vessels. Removal of endothelium prior to culture abolished these effects. All-trans retinoic acid …

A Medicinal Plant Survey In Marketplaces Of Ecuador, Pamela Bailey

Theses, Dissertations and Capstones

A medicinal herb survey was conducted in ten major marketplaces in Andean and coastal communities of Ecuador. Collections were made during the summer of 1997. Four plant collections from each market were pressed, dried, identified, and the medicinal information for each plant was recorded. Photographs of fresh plants, market vendors and the marketplaces were taken.

Fifty three families were represented in the 112 species collected. Forty-two species (37%) were introduced to Ecuador while seventy species (63%) were native to Ecuador. Plant taxa were grouped into 22 categories of medicinal usage. The most common 3 uses were: 1. General tonic and …

32p-Postlabeling Analysis Of Aromatic Dna Adducts In Hemopoietic Tissues And Blood Of The Mummichog Fundulus Heteroclitus, Wendy L. Rose

Dissertations, Theses, and Masters Projects

No abstract provided.

Functional And Molecular Analysis Of Antibody Affinity Maturation In Rainbow Trout (Oncorhynchus Mykiss), Haili Zhang

Dissertations, Theses, and Masters Projects

No abstract provided.

Indo-Pacific Population Structure Of The Black Marlin, Makaira Indica, Inferred From Molecular Markers, Brett Falterman

Dissertations, Theses, and Masters Projects

No abstract provided.

Environmental Stress In Hard Coral: Evaluating Lipid As An Indicator Of Sublethal Stress On Short Time Scales, David Harold Niebuhr

Dissertations, Theses, and Masters Projects

Lipid quality was evaluated in Montastrea spp. under sediment- and heat-stressed conditions to evaluate lipid ratio as an indicator of sub-lethal stress on short time scales. The ratio of storage lipid (wax ester + triacylglyceride) to structural lipid (sterol esters + phospholipid) decreased significantly (0.25 to 0.14, p < 0.01) after experimental sedimentation. FAME analysis of colonies exposed to experimental sedimentation showed a reduction of the algal, 18:3(n-6) and 18:4(n-3), polyunsaturated fatty acid (PUFA) in the polar lipid fraction. This loss of PUFA suggests a loss of algal membrane in sediment-stressed colonies. Lipid quality was similarly measured in M. faveolata over a 10-day period. Mean (n = 20) ratio of storage to structural lipid in M. faveolata dropped from 2.43 to a level of 0.98 immediately following a natural sedimentation event before recovering to levels of 1.4 and 2.9 on post-storm days 2 and 4, respectively. Colonies of M. annularis subject to heat-stress (35??C) exhibited no significant change in storage lipid ratio, while levels of Free Fatty Acids increased significantly from 0.012 (n = 22) to 0.156 mg lipid/g dry tissue (n = 22)(p < 0.05). FAME analysis of tissue lipids extracted from the heat-stressed colonies showed changes in the polar fraction, with significant decreases in the 18:3(n-6), 18:3(n-3), 18:4(n-3), 20:4(n-6) and 20:5(n-3) (p < 0.05) PUFA and subsequent significant increases in the saturated fatty acids, 16:0 and 18:0 (p < 0.05). These changes in lipid quantity and quality indicate possible oxidation and preferential digestion of zooxanthellar membranes. Stress experiments were repeated in M. annularis using VacutainerRTM blood collection tubes to collect micro-tissue samples without destroying skeleton of the sample colonies. A significant decrease in storage: structural lipid ratio after sedimentation was also detected using the micro-tissue technique. This study indicates that the relative abundance of lipid subclass components can indicate sub-lethal environmental stress, on short time scales, in M. annularis and M. faveolata. Furthermore, micro-tissue collection techniques permit repeated monitoring coral colonies to assess the manifestation of stress from first detection of impact at the cellular level to changes in community to changes in community structure detectable over longer time scales.

Detection Of Ehrlichia Chaffeensis In Ticks Of The Georgia Coast And Barrier Islands Using Polymerase Chain Reaction, John Edward Whitlock

Legacy ETDs

Human monocytic ehrlichiosis (HME) is an emerging, zoonosis transmitted to mammals by ixodid ticks. Prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation and human disturbance. To test this, individual and pooled lone star ticks, Amblyomma americanum (L.), collected from 3 populations from the coast and barrier islands of Georgia were screened for Ehrlichia chaffeensis Anderson, Dawson, Jone, and Wilson, the agent of HME. A species-specific, nested polymerase chain reaction (PGR) assay was used to amplify a 572 base pair fragment of …

Molecular Phylogeny Of Lake Baikal Amphipods, Kenneth S. Macdonald

Dissertations, Theses, and Masters Projects

No abstract provided.

Construction Of An Escherichia Coli Lac Repressor-Based System To Study Human Cytomegalovirus Gene Expression, Laura Fernanda Cageao-Luchetti

Theses and Dissertations in Biomedical Sciences

An Escherichia coli lac repressor-based system was developed to study the roles of human cytomegalovirus (HCMV) genes during viral replication. To this end, a recombinant HCMV expressing the lac repressor was generated (RVlac), and an HCMV-specific promoter was targeted for conditional expression by inserting the lac operator sequence. The promoter of a nonessential gene was chosen in order to be able to assess parameters of repression and derepression of the operator-containing promoter in the endogenous locus, without having virus growth dependent on the specific inducer isopropylthiogalactoside (IPTG). The feasibility of this approach to conditionally express an HCMV promoter …

Characterization Of Rat Pulmonary Carboxylesterase, Timothy J. Wallace

Theses and Dissertations

The 1839 bp cDNA for rat pulmonary carboxylesterase was cloned by reverse transcription polymerase chain reaction (RT PCR) from total rat lung RNA using specific primers derived from the 5' and 3' untranslated regions of rat hepatic cholesteryl ester hydrolase (CEH). The unique cDNA was sequenced and found to have 99% homology with hepatic CEH. This homology extends to the predicted amino acid sequences which show only six amino acid residue differences in the coding region: three conserved and three nonconserved changes. However, the catalytic activitites of the two proteins are dramatically different. While CEH hydrolyzes cholesterol oleate, the pulmonary …

Temporal And Spatial Variation In Abundance Of Migratory Birds At Kennesaw Mountain, Georgia, Andrew Allen Kinsey

Legacy ETDs

Migratory birds spend a significant part of each year in transition between their breeding and resting grounds. During this transitional period migrants rely on stopover sites to provide them with the necessary habitat to replenish lost energy stores, rest, and wait for favorable weather conditions before continuing migration. The majority of stopover work related to passerines in North America has occurred along coastal migration routes. Meanwhile, relatively little work has been conducted at inland stopover sites, areas which may be equally important to migrating birds. Kennesaw Mountain is an isolated geographically prominent peak located in the foothills of the southern …

The Atomic Force Microscope In The Elucidation Of Leukocyte Abnormality, Derbrenn O'Connor

Theses

The aim of this project was to investigate the novel use of the atomic force microscope (AFM) as a technique in the elucidation of leukocyte abnormality. To this end, comparative AFM imaging and elasticity studies were performed on normal and myeloid leukaemic leukocytes.

Initially, an evaluation of techniques for the isolation of specific leukocyte (e.g. lymphocytes, granulocytes, etc.) populations from whole blood or leukocyte concentrates, was carried out. It was found that a silanised glass surface failed to select and immobilise a leukocyte population. However, centrifugation of whole blood in an Isopaque-ficoll gradient solution yielded a viable mixed leukocyte population …

Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem

Masters Theses

Regulatory mechanisms of malate dehydrogenase from E.coli (eMDH) involving NADH as an allosteric effector were investigated. The reaction was studied in both directions: malate oxidation and oxaloacetate reduction. When malate was the variable substrate, a plot of rate against substrate concentration was sigmoidal in the presence of 0.065 mM NADH, which indicates the presence of an allosteric site for NADH on the enzyme. Binding of NADH at the allosteric site causes conformational changes in the active site and, thereby, changes the catalytic activity of the enzyme. An increase in K_m value, from 1.3 to 3.9 mM malate was observed, …