Membrane Science Commons^™

Development Of A New Affinity Membrane For Rapidly Purifying Non-Antibody Proteins, Friendship Edioma

All Theses

This thesis project describes the modification and evaluation of a new affinity membrane for rapid chromatographic purification of non-antibody proteins. The affinity membrane utilizes Im7/CL7 coupling technology developed by Dr. Vassylyev's lab at the University of Alabama Birmingham (UAB), licensed by TriAltus Bioscience. The behavior of the membrane was evaluated using purified CL7-tagged Cas9 as my model protein for static and dynamic binding capacity analysis.

Chapter one provides an overview on biopharmaceutical drug production process development. I discuss how protein drugs are produced, isolated, and purified from the cell supernatant after upstream phases are completed. Despite increasing demands for biologics, …

Lipoprotein-Induced Increases In Cholesterol And 7-Ketocholesterol Result In Opposite Molecular-Scale Biophysical Effects On Membrane Structure, Manuela A.A. Ayee, Irena Levitan

Faculty Work Comprehensive List

Under hypercholesterolemic conditions, exposure of cells to lipoproteins results in a subtle membrane increase in the levels of cholesterol and 7-ketocholesterol, as compared to normal conditions. The effect of these physiologically relevant concentration increases on multicomponent bilayer membranes was investigated using coarse-grained molecular dynamics simulations. Significant changes in the structural and dynamic properties of the bilayer membranes resulted from these subtle increases in sterol levels, with both sterol species inducing decreases in the lateral area and inhibiting lateral diffusion to varying extents. Cholesterol and 7-ketocholesterol, however, exhibited opposite effects on lipid packing and orientation. The results from this study indicate …

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …

Functional Importance Of Lipin Phosphorylation, Stephanie Elizabeth Hood

Graduate Theses and Dissertations

Highly conserved throughout evolution, lipins are dual functioning proteins found from yeast to humans. Functioning in the cytoplasm as phosphatidate phosphatase enzymes (PAP), lipins produce diacylglycerol that serves as a precursor for neutral fats and membrane phospholipids. Alternatively, nuclear lipins are responsible for the regulation of metabolic genes. Interestingly, both the mammalian lipin 1 paralog and the single Drosophila Lipin ortholog are highly phosphorylated proteins. Target of rapamycin (TOR) has previously been identified as one of the kinases that controls the subcellular localization of both lipin 1 and Drosophila Lipin. However, other serine and threonine kinases are predicted to be …

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …

Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson

Biomedical Engineering Undergraduate Honors Theses

Amyloid Beta (Aβ) was the major focus of this study. It is a peptide that is present in the brain with a high tendency to self-aggregate. When this protein aggregates, it forms oligomers and protofibrils which in turn are deposited as senile plaques in the brain. The reason for the concern with these plaques is their association with the neurological disorder Alzheimer’s disease. It has been found that the most dangerous oligomers are formed in a portion of the plasma membrane known as lipid rafts. The purpose of this study was to understand how micelles affect the aggregation properties of …

Longitudinal Study Of Plasma And Erythrocyte Selenium Levels In Type I Diabetic Children During Development And Treatment Of Ketoacidosis, Pi-Hsia Fan

Chemistry & Biochemistry Theses & Dissertations

Most studies on the biological activity of selenium have focused on its role at the active site in the ubiquitous enzyme, glutathione peroxidase (GSH-Px) which catalyzes the removal of hydrogen peroxide and organic hydroperoxides (1). A connection between selenium deficiency and a wide range of diseases in animals and humans has been reviewed (2). Development of various forms of human cancer (3), failure of the immune system (4), as well as some cardiovascular diseases (5) have been reported or suspected to correlate with selenium deficiency. However, the physiological function of selenium in these different diseases is not fully understood, and …