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Glucose Transporter Oligomeric Structure Determines The Mechanism Of Glucose Transport: A Dissertation, Daniel N. Hebert Dec 1991

Glucose Transporter Oligomeric Structure Determines The Mechanism Of Glucose Transport: A Dissertation, Daniel N. Hebert

GSBS Dissertations and Theses

The relationship between human erythrocyte glucose transporter (GLUT1) oligomeric structure and function was studied. GLUT1 was purified from human erythrocytes in the absence (GLUT1-DTT) or the presence (GLUT1+DTT) of dithiothreitol. Chemical cross-linking studies of lipid bilayer-resident purified GLUT1 and hydrodynamic studies of cholate-solubilized GLUT1 support the view that GLUT1-DTT is a homotetramer and GLUT1+DTT is a homodimer. Parallel studies on human erythrocyte, and studies employing conformation-specific antibodies (anti-GLUT1-DTT antibodies, ∂-IgGs), indicate that erythrocyte-resident GLUT1 resembles GLUT1-DTT (a homotetramer). While the D-glucose binding capacities of GLUT1-DTT and GLUT1+DTT are indistinguishable, GLUT1-DTT presents at least two population of binding ...


Repair Of Dna Containing Small Heterologous Sequences By Escherichia Coli: A Dissertation, Breck Olland Parker Nov 1991

Repair Of Dna Containing Small Heterologous Sequences By Escherichia Coli: A Dissertation, Breck Olland Parker

GSBS Dissertations and Theses

The Dam-dependent mismatch repair system of Escherichia coli is part of a large network of DNA surveillance and error avoidance systems that identify and repair DNA damage. In this thesis, I have investigated the Dam-dependent mismatch repair system of E. coliand its role in the recognition and repair of DNA substrate molecules containing small insertion/deletion heterologies. This investigation was divided into two parts: the first part utilized genetic techniques to evaluate the specificity of repair and the second part utilized biochemical approaches into the recognition of insertion/deletion heterologies.

I have developed a sensitive in vivo transformation system ...


Small B Cells As Antigen Presenting Cells In The Induction Of Tolerance To Soluble Protein Antigens: A Dissertation, Elizabeth E. Eynon Sep 1991

Small B Cells As Antigen Presenting Cells In The Induction Of Tolerance To Soluble Protein Antigens: A Dissertation, Elizabeth E. Eynon

GSBS Dissertations and Theses

This thesis proposes a mechanism for the induction of peripheral tolerance to protein antigens. I have investigated the mechanism of tolerance induction to soluble protein antigens by targeting an antigen to small, resting B cells. For this purpose I have used a rabbit antibody directed at the IgD molecule found on the surface of most small, resting B cells but missing or lowered on activated B cells. Intravenous injection of normal mice with 100 μg of an ultracentrifuged Fab fragment of rabbit anti-mouse IgD (Fab anti-δ) makes these mice profoundly tolerant to challenge with nonimmune rabbit Fab (Fab NRG) fragments ...


Transcriptional Control Of Human Histone Gene Expression: Delineation And Regulation Of Protein/Dna Interactions: A Thesis, Andre John Van Wijnen May 1991

Transcriptional Control Of Human Histone Gene Expression: Delineation And Regulation Of Protein/Dna Interactions: A Thesis, Andre John Van Wijnen

GSBS Dissertations and Theses

Transcriptional regulation of cell cycle controlled genes is fundamental to cell division in eukaryotes and a broad spectrum of physiological processes directly related to cell proliferation. Expression of the cell cycle dependent human H4, H3 and H1 histone genes is coordinately regulated at both the transcriptional and posttranscriptional levels. We have systematically analyzed the protein/DNA interactions of the immediate 5'regions of three prototypical cell cycle controlled histone genes, designated H4-F0108, H3-ST519 and H1-FNC16, to define components of the cellular mechanisms mediating transcriptional regulation.

Multiple biochemically distinct protein/DNA interactions were characterized for each of these genes, and the ...


Regulation Of Transcription Of Mouse Immunoglobulin Germ-Line Γ1 Rna: Structural Characterization Of Germ-Line Γ1 Rna And Molecular Analysis Of The Promoter: A Dissertation, Minzhen Xu May 1991

Regulation Of Transcription Of Mouse Immunoglobulin Germ-Line Γ1 Rna: Structural Characterization Of Germ-Line Γ1 Rna And Molecular Analysis Of The Promoter: A Dissertation, Minzhen Xu

GSBS Dissertations and Theses

The antibody class switch is achieved by DNA recombination between the sequences called switch (S) regions located 5' to immunoglobulin (Ig) heavy chain constant (CH) region genes. This process can be induced in cultured B cells by polyclonal stimulation and switching can be directed to specific antibody classes by certain lymphokines. These stimuli may regulate the accessibility of CH genes and their S regions to a recombinase as indicated by hypomethylation and transcriptional activity. For example, RNAs transcribed from specific unrearranged (germ-line) CH genes are induced prior to switching under conditions that promote subsequent switching to these ...


Virus-Lymphocyte Interactions: Virus Expression Is Differentially Modulated By B Cell Activation Signals: A Dissertation, Madelyn R. Schmidt Jan 1991

Virus-Lymphocyte Interactions: Virus Expression Is Differentially Modulated By B Cell Activation Signals: A Dissertation, Madelyn R. Schmidt

GSBS Dissertations and Theses

It is shown here that the ability of B lymphocytes to act as supportive host cells for virus infections requires they be activated from the resting Gostage of the cell cycle. I have used a series of activation regimens, which allow B cells to progress to different stages in their activation/differentiation pathway toward antibody secretion, in order to evaluate the extent of activation required to support vesicular stomatitis or Newcastle disease virus infections.

At least three distinct phases during B cell activation which affected VSV infection were defined. Freshly isolated resting murine splenic B cells in the ...