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Targeted Gene Replacement To Mimic Familial Hypertrophic Cardiomyopathy In Caenorhabditis Elegans, Craig Alan Almeida

Doctoral Dissertations

The identification in invertebrates of genes homologous to human disease genes provides the possibility to broaden the spectrum of model organisms to include experimental invertebrates. The goal of this study is to test the possibility of using Caenorhabditis elegans as an animal model for the inherited human heart disorder familial hypertrophic cardiomyopathy. In 10-30% of the affected families that have been studied, this disease is caused by mutations in the $\beta$-cardiac myosin heavy chain (MHC) gene. The most common of these mutations results in the replacement of an evolutionarily conserved arginine residue (R403) with glutamine (R403Q). While this information has …

Regulation Of Interrenal Steroidogenesis In Elasmobranchs., Brian Scott Nunez

LSU Historical Dissertations and Theses

This study investigated the steroidogenic enzymes of the elasmobranch interrenal. First, biochemical characteristics of cytochrome P450c21 hydroxylase (P450c21) and 3$\beta$-hydroxysteroid dehydrogenase (3$\beta$-HSD) were determined with incubations of the microsomal fraction of Carcharhinus limbatus (blacktip shark) interrenal tissue. Second, molecular reagents were obtained by isolating and sequencing partial cDNA clones encoding the elasmobranch steroidogenic enzymes cytochrome P450 side chain cleavage (P450scc) and 3$\beta$-HSD from blacktip shark and Daysatis americana (southern stingray) interrenal. Finally, the regulation of Daysatis sabina (Atlantic stingray) interrenal steroidogenesis by peptide hormones such as corticotropin (ACTH) and angiotensin II was investigated by in vitro incubations of interrenal tissue. …

The Purification And Characterization Of An Extrapallial Fluid Protein From The Mollusc, Mytilus Edulis, Stephen Joseph Hattan

Doctoral Dissertations

Shell deposition within the bivalve mollusc Mytilus edulis is regulated by the macromolecules of the extrapallial fluid (EP fluid). These mineralization regulating macromolecules are thought to be responsible for the nucleation, growth regulation and growth cessation of the CaCO$\sb3$ mineral crystals that will inevitable constitute $\geq$95% of the mature shell.

This dissertation presents the results of the purification and characterization of the major EP fluid protein of the bivalve Mytilus edulis. The major EP fluid protein was determined to comprise 56% of the total fluid protein and to consist of 7.25% by weight carbohydrate. The protein was purified though a …

Investigation Of Pd(A)(20)Pd(T)(20) In The Analytical Electrophoresis Apparatus, John Oliver Wooll

Doctoral Dissertations

The analytical electrophoresis apparatus (AEA) is capable of generating and monitoring the electrophoretic migration of macroions. The oligonucleotide pd(A)$\sb{20}\cdot$pd(T)$\sb{20}$ was use as a model to compound to evaluate the range and validity of AEA measurements under a variety of electric fields and solvent conditions. A broad range of electric fields yield consistent, reproducible values. The charge determination from different procedures, steady state electrophoresis (SSE) and electrophoretic mobility, have not been consolidated into a consistent theory but advancements in the scope and understanding of the AEA's potential have been made. The apparent charge from the AEA measured electrophoretic mobility, $\mu$, of …

The Cytoplasmic N,N'-Diacetylchitobiase Gene From Vibrio Parahaemolyticus: Sequence Analysis, Protein Secretion, And Secretion System Development., Michael Hongli Wu

LSU Historical Dissertations and Theses

The nucleotide sequence of the gene encoding the cytoplasmic $N,N\sp\prime$-diacetylchitobiase from Vibrio parahaemolyticus has been determined. The deduced peptide sequence surprisingly has minimum evolutionary relationship to two other reported $N,N\sp\prime$-diacetylchitobiases from vibrios, except for highly conserved regions which are also homologous with lysosomal beta-hexosaminidases from eukaryotes including humans. In contrast, the other two sequenced chitobiases from vibrios are much more closely related to each other. This 85 kDa cytoplasmic protein, as revealed from the sequence, appears to be a unique protein, lacking a signal sequence and genetically distant from other known enzymes of similar function. This is consistent with its …

Biochemical And Biophysical Studies Of Wild-Type And Active-Site Mutants Of Human Adenosine Deaminase., Qing Zeng

LSU Historical Dissertations and Theses

The focus of this work is structural and functional studies of wild-type and active-site mutants of human adenosine deaminase. Two active-site amino acids, Glu217 and His238, were previously substituted with alanine by site-directed mutagenesis. The Glu217Ala and His238Ala mutants showed little or no changes in Zn content and $\rm K\sb{m}$ value, yet dramatic loss of enzyme activity. Circular dichroism studies of the solution conformation of wild-type and mutant human adenosine deaminases indicate that 30 to 50% of $\alpha$-helical structure is lost in Glu217Ala and His238Ala, respectively, whereas $\beta$-sheet structure is fully retained. Inhibitor binding is measured by a fluorescent assay. …

Dinitropyrenes: Nitroreduction Processes And Evaluation Of Indices Of Exposure., Matthew Jerome Krautmann

LSU Historical Dissertations and Theses

Investigations were conducted to identify biomarkers of exposure to dinitropyrenes (DNPs), which are mutagenic and carcinogenic residues of incomplete combustion. One possible biomarker, a DNP-protoporphyrin IX adduct, was not found in analytically useful quantities in liver tissue or in bile. Clastogenicity, a biomarker of effect, also was found to be absent in marrow cells following subchronic exposure of rats to DNPs by gavage. Solubility studies, used as a basis for dosing guidelines, revealed that DNPs are relatively insoluble in both aqueous and lipid tissue compartments. Calculated log P values indicated that the reduced metabolites of DNPs probably are more soluble …

Synthesis Of Novel Amino Acids With Incorporation Into Peptides And Synthesis Of Peptides With Novel Aggregation States., Scott Michael Cowell

LSU Historical Dissertations and Theses

Peptides exhibit properties based on the amino acids present in the peptide and structure the peptide assumes in its environment. For example, peptides have been shown to be antimicrobial when they are amphipathic and in an $\alpha$-helical shape. The mechanism for this antimicrobial activity is subject to dispute. One theory states that the peptides work by forming a "pore" through the cell membrane which causes a depolarization of the membrane and the cell lysis because of osmosis. Another theory states that the peptides merely compromise the integrity of the membrane by solubilizing the membrane. In order for the "pore" theory …

Astroglial Insulin-Like Growth Factor Binding Proteins: Regulation Of Synthesis And Relationship To Cell Growth, Sheri Lynn Bradshaw

Digitized Theses

The insulin-like growth factors (IGFs) regulate the growth and differentiation of a wide variety of tissues, including the brain. The biologic actions of IGFs are modulated by a family of six IGF binding proteins (IGFBPs), which, like IGFs, are synthesized as paracrine factors. We hypothesized that the IGFBPs synthesized by astroglial cells, are regulated by growth factors produced in the developing brain, and modulate the growth of these cells. Primary astroglial cells synthesized IGFBP-2 and IGFBP-3 which were upregulated in a dose dependent manner by IGF-I, IGF-II, and very high concentrations of insulin, suggesting that the growth factors regulate their …

Some Physiological Effects Of Stress In The American Cockroach Periplaneta Americana (L), Shigui Liu

Digitized Theses

The effects of different forms of stress on the American cockroach, Periplaneta americana (L.) have been systematically examined. This study demonstrated that at least two stress-related events occurred in the haemolymph of the American cockroach. First, the data clearly indicated that a large increase in hypertrehalosemic hormones occurred in the haemolymph of stressed cockroaches. Secondly, proteolytic activity in the haemolymph of stressed cockroaches was greatly increased. The increase of both hypertrehalosemic hormones and proteolytic activity in the haemolymph appeared to be a non-specific response to different forms of stress, including chemical poisoning with lindane, immobilization, forced movement, starvation, and elevated …