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Full-Text Articles in Molecular Biology

Genetic And Biochemical Analysis Of Aspergillus Awamori Glucoamylase Thermostability , Martin John Allen Jan 1997

Genetic And Biochemical Analysis Of Aspergillus Awamori Glucoamylase Thermostability , Martin John Allen

Retrospective Theses and Dissertations

Aspergillus awamori glucoamylase (GA) is an enzyme involved in industrial corn starch processing. Genetic and biochemical approaches were used to study the mechanisms governing GA thermostability. Three proline substitution (Xaa → Pro) mutations were constructed that were predicted to increase the enzyme's stability by decreasing its conformational entropy of unfolding. When expressed in Saccharomyces cerevisiae Ser30 → Pro increased, Asp345 → Pro did not alter and Glu408 → Pro greatly decreased GA stability as measured by resistance to irreversible thermoinactivation relative to the wild-type enzyme. The Ser30 → Pro mutation was combined with other previously identified stabilizing mutations to examine whether combining such mutations ...


Cloning, Expression And Bioactivity Of Porcine Soluble Tnf Receptor 1 And The Comparison Of Pk(15) And Wehi 164(13)-Based Tnf Bioassays , Nancy A. Maroushek Boury Jan 1997

Cloning, Expression And Bioactivity Of Porcine Soluble Tnf Receptor 1 And The Comparison Of Pk(15) And Wehi 164(13)-Based Tnf Bioassays , Nancy A. Maroushek Boury

Retrospective Theses and Dissertations

Tumor necrosis factor (TNF) is a pro-inflammatory cytokine that activates both leukocytes and endothelium and facilitates the movement of inflammatory cells from circulation to sites of infection or injury. This activation may be beneficial and aid in host defense, or may be detrimental and mediate part of the pathophysiology of disease. Several porcine diseases, such as salmonellosis and mycoplasmal pneumonia, cause an increase in TNF production, which may be either beneficial or harmful to swine health. Two related studies were completed to develop assays and reagents to further study the role of TNF in porcine disease;In the first study ...


Organization And Expression Of The Tup Gene In Daucus Carota , Philip Earl Dykema Jan 1997

Organization And Expression Of The Tup Gene In Daucus Carota , Philip Earl Dykema

Retrospective Theses and Dissertations

Differential screening of a somatic embryo cDNA library for genes expressed during embryogenesis has disclosed a small RNA which I have named Tiny Up-regulated Protein (TUP). This mRNA is 402 bp in length, is expressed during embryo formation, and reaches its highest accumulation in the flowers and roots of adult carrot plants. The mRNA is barely detectable in leaves. The accumulation of the TUP mRNA in seedlings is increased by auxin and by abscisic acid. The open reading frame encodes a tiny, uniquely structured protein of 6100 Daltons which has a pI of 5.3. Algorithms predicting protein structure suggest ...


Gene Expression Studies Of Murine Pregnancy Associated Granulated Metrial Gland And Decidual Cells , Melissa Phillips Allen Jan 1997

Gene Expression Studies Of Murine Pregnancy Associated Granulated Metrial Gland And Decidual Cells , Melissa Phillips Allen

Retrospective Theses and Dissertations

During pregnancy in viviparous mammals, the maternal decidua develops between the embryo and the uterine endometrium. This dissertation describes research on two different cell types present within the rodent decidua during pregnancy, namely, granulated metrial gland (GMG) cells and decidual cells;GMG cells are natural killer cells that proliferate and differentiate within the murine uterus during pregnancy. Their differentiation is associated with the accumulation of cytolytic mediators within cytoplasmic granules. The signaling mechanisms required for GMG cell differentiation, however, are largely unknown. In this study, expression of the genes coding for granzymes D, E, F, and G (granzymes D-G) was ...


Molecular Cloning And Characterization Of Gl8, A Gene Involved In Maize Cuticular Wax Biosynthesis , Xiaojie Xu Jan 1997

Molecular Cloning And Characterization Of Gl8, A Gene Involved In Maize Cuticular Wax Biosynthesis , Xiaojie Xu

Retrospective Theses and Dissertations

The gl8 locus of maize was previously defined by a mutation that reduces the amount and alters the composition of seedling cuticular waxes. Sixty independently derived gl8 mutant alleles have been isolated from stocks that carried the Mutator transposon system. A DNA fragment that contains a Mu8 transposon and that co-segregates with one of these alleles, gl8-Mu3142, was identified and cloned. DNA flanking the Mu8 transposon was shown to represent the gl8 locus via allelic cross-referencing experiments. The gl8 probe reveals a 1.4-kb transcript present in wild-type seedling leaves, and in lesser amounts, in other organs and at other ...


Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang Jan 1997

Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang

Retrospective Theses and Dissertations

Specific carbohydrate structures on neural cell adhesion molecules are promising candidates for assisting in patterning neural connections during development. An excellent system to study the potential function of specific oligosaccharide modifications of neural proteins regulating pathway formation is in the projections of sensillar neurons in leech. At least five different monoclonal antibodies (Lan3-2, Lan2-3, Lan4-2, Laz2-369, Laz7-79) which recognize different glycoepitopes specific to the entire population as well as distinct subsets of these sensillar neurons have been identified. Their expression patterns and antibody perturbation studies are consistent with the hypothesis that a hierarchy of distinct carbohydrate structures expressed by specific ...


Replication Of Barley Yellow Dwarf Luteovirus-Pav Rna , Mohan Bangalore Jan 1997

Replication Of Barley Yellow Dwarf Luteovirus-Pav Rna , Mohan Bangalore

Retrospective Theses and Dissertations

Barley yellow dwarf luteovirus (BYDV)-PAV serotype, an economically important virus of small grain cereals, has a positive-sense RNA genome encoding at least six open reading frames (ORFs). The goal of the research was to determine the genes and sequences involved in the viral replication and to design efficient antiviral strategies to BYDV-PAV. Genetically engineered resistance is essential for BYDV as the natural resistance is inadequate. Antiviral constructs such as sense RNA, antisense RNA and viral polymerase gene were tested for their ability to reduce virus titre in oat protoplasts as monitored by enzyme-linked immunosorbent assay. All antiviral constructs yielded ...


Identification And Characterization Of Proteins Binding To Regulatory Elements Of The Hoxa-5 Spatial-Specific Enhancer , Tamara Mann Nowling Jan 1997

Identification And Characterization Of Proteins Binding To Regulatory Elements Of The Hoxa-5 Spatial-Specific Enhancer , Tamara Mann Nowling

Retrospective Theses and Dissertations

The Hox homeobox genes cooperate in providing positional information needed for spatial and temporal patterning of the vertebrate body axis. However, the biological mechanisms behind spatial Hox expression are largely unknown. In transgenic mice, gene fusions between Hoxa-5 (previously called Hox-1.3) 5' flanking regions and lacZ show tissue- and time-specific expression in the brachial spinal cord in day 11-13 embryos. This spatially-specific expression is directed by a 604 bp regulatory region with enhancer properties. Fine-detail mapping of this enhancer has identified several elements involved in region-specific expression. A brachial spinal cord (BSC) element, is required for expression in the ...


Suppressor Analysis Of The Protein Kinase Elm1p, An Enzyme Involved In The Regulation Of Yeast Morphology , Nicholas Patrick Edgington Jan 1997

Suppressor Analysis Of The Protein Kinase Elm1p, An Enzyme Involved In The Regulation Of Yeast Morphology , Nicholas Patrick Edgington

Retrospective Theses and Dissertations

Saccharomyces cerevisiae is an ascomycete that has several developmental options, with concomitant morphological changes, that depend on cell type and nutrient status. In response to these signals, vegetative Saccharomyces cerevisiae cells assume one of two distinct morphologies, the yeast form or the filamentous form. Molecules affecting this morphogenetic response were identified by analyzing transposon-induced or spontaneous suppressor mutations that restore yeast form growth to a strain that constitutively exhibits filamentous form characteristics owing to mutation of the protein kinase Elm1p. One transposon-tagged mutation was isolated and is allelic to the negative regulatory subunit Bcy1p, thus activation of cAMP dependent protein ...


Studies Of Cis- And Trans-Acting Elements In Tetrahymena Rdna Replication , Chunying Du Jan 1997

Studies Of Cis- And Trans-Acting Elements In Tetrahymena Rdna Replication , Chunying Du

Retrospective Theses and Dissertations

Eukaryotic cells must precisely duplicate their genomes before they divide. The mechanisms of eukaryotic chromosomal DNA replication are far from clear, however, because very few cis- and trans-acting factors that function in eukaryotic DNA replication have been identified. To gain further insights into this problem, this work identified and characterized potential cis- and trans-acting replication factors for the replication initiation of Tetrahymena ribosomal RNA gene (rDNA);A search far cis-acting elements identified a cluster of predicted modular sequences and structural elements in the origin region of rDNA. The presence of these elements were verified experimentally; (1) two mung bean nuclease-hypersensitive ...