Biophysics Commons^™

Analysis Of The Phosphorylated Forms Of Protein Kinase R, Christine Quartararo

Honors Scholar Theses

Protein Kinase R (PKR) is induced by interferon and activated by dsRNA. Subsequent autophosphorylation and phosphorylation of eIF2alpha inhibits viral replication. In the latent state PKR exists as an unphosphorylated monomer. Work in the Cole laboratory has shown two additional states, a phosphorylated monomeric state (pPKRm) and a phosphorylated dimeric state (pPKRd). RNA serves as a scaffold bringing two PKRs together allowing dimerization and autophosphorylation to occur. The contribution of each state to the function of PKR remains unclear. Western blots were performed to examine the phosphorylation states of the essential residues,

T446 and T451. Activity assays have shown activation …

Human Cerebral Neuropathology Of Type 2 Diabetes Mellitus, Peter T. Nelson, Charles D. Smith, Erin L. Abner, Frederick A. Schmitt, Stephen W. Scheff, Gregory J. Davis, Jeffrey N. Keller, Gregory A. Jicha, Daron Davis, Wang-Xia Wang, Adria Hartman, Douglas G. Katz, William R. Markesbery

Pathology and Laboratory Medicine Faculty Publications

The cerebral neuropathology of Type 2 diabetes (CNDM2) has not been positively defined. This review includes a description of CNDM2 research from before the ‘Pubmed Era’. Recent neuroimaging studies have focused on cerebrovascular and white matter pathology. These and prior studies about cerebrovascular histopathology in diabetes are reviewed. Evidence is also described for and against the link between CNDM2 and Alzheimer's disease pathogenesis. To study this matter directly, we evaluated data from University of Kentucky Alzheimer's Disease Center (UK ADC) patients recruited while non-demented and followed longitudinally. Of patients who had come to autopsy (N = 234), 139 met …

Phosphorylation Of The Estrogen Receptor Alpha (Erα) At Serine 118 By Phospho-P44/42 Mapk And Regulation By Estrogen And Progesterone In Human Uterine Leiomyoma Tissue And Cells, Tonia Lakisha Hermon

Theses and Dissertations in Biomedical Sciences

It is thought that the growth of uterine leiomyomas may be mediated by the interaction of estrogen receptor alpha (ERα) and growth factor pathways and that phosphorylation of ERα at serine 118 (ERα-phospho-Ser118) is important in this interaction. In tissue, immunoblotting and immunohistochemistry were used to investigate the expression of ERα-phospho-Ser118, phosphorylated p44/42 mitogen-activated protein kinase (phospho-p44/42 MAPK), and proliferating cell nuclear antigen (PCNA) in human leiomyoma and myometrial tissues during the proliferative and secretory phases of the menstrual cycle. In vitro studies to assess proliferation of uterine leiomyoma (UtLM) and uterine smooth muscle (UtSMC) cells and expression of ERα-phospho-Ser118 …

From Powder To Solution: Hydration Dependence Of Human Hemoglobin Dynamics Correlated To Body Temperature, A. M. Stadler, I. Digel, J. P. Embs, T. Unruh, Moeava Tehei, G. Zaccai, G. Büldt, G. M. Artmann

Faculty of Science - Papers (Archive)

A transition in hemoglobin (Hb), involving partial unfolding and aggregation, has been shown previously by various biophysical methods. The correlation between the transition temperature and body temperature for Hb from different species, suggested that it might be significant for biological function. In order to focus on such biologically relevant human Hb dynamics, we studied the protein internal picosecond motions as a response to hydration, by elastic and quasielastic neutron scattering. Rates of fast diffusive motions were found to be significantly enhanced with increasing hydration from fully hydrated powder to concentrated Hb solution. In concentrated protein solution, the data revealed that …

Regulation Of Intracellular Calcium Concentration By Nanosecond Pulsed Electric Fields, Shaka S. Scarlett, Jody A. White, Peter F. Blackmore, Karl H. Schoenbach, Juergen Kolb

Bioelectrics Publications

Changes in [Ca²⁺]_i response of individual Jurkat cells to nanosecond pulsed electric fields (nsPEFs) of 60 ns and field strengths of 25, 50, and 100 kV/cm were investigated. The magnitude of the nsPEF-induced rise in [Ca²⁺]_i was dependent on the electric field strength. With 25 and 50 kV/cm, the [Ca²⁺]_i response was due to the release of Ca²⁺ from intracellular stores and occurred in less than 18 ms. With 100 kV/cm, the increase in [Ca²⁺]_i was due to both internal release and to influx across the plasma …

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Study Of Dynamic Processes In Protein Synthesis Using Heterogeneous Ribosome Specimens, Jie Fu

Legacy Theses & Dissertations (2009 - 2024)

Single-particle reconstruction from cryo-electron microscopy (cryo-EM) images is a widely used technique in studying the structure of macromolecular complexes. This technique allows the visualization of molecules in their native hydrated state. The heterogeneity of two-dimensional projection images, resulting from the co-existence of different states of a macromolecular complex, remains a major obstacle, as it impairs the validity of reconstruction and limits the progress toward higher resolution. On the other hand, co-existing structures, if successfully extracted from a single dataset, can provide valuable information about the equilibrium and dynamics of the biological system being studied.

Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Xiangchun Xuan, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

Pressure-driven transport of particles through a symmetric converging-diverging microchannel is studied by solving a coupled nonlinear system, which is composed of the Navier-Stokes and continuity equations using the arbitrary Lagrangian-Eulerian finite-element technique. The predicted particle translation is in good agreement with existing experimental observations. The effects of pressure gradient, particle size, channel geometry, and a particle's initial location on the particle transport are investigated. The pressure gradient has no effect on the ratio of the translational velocity of particles through a converging-diverging channel to that in the upstream straight channel. Particles are generally accelerated in the converging region and then …

Molecular Dynamics Study Of Single Stranded Peptide Nucleic Acids, Anna K. Manukyan

Theses and Dissertations in Biomedical Sciences

A PNA molecule is a DNA strand where the sugar-phosphate backbone has been replaced by a structurally homomorphous pseudopeptide chain consisting of N(2-aminoethyl)-glycine units. PNA binds strongly to both DNA and RNA. However, an analysis of the X-ray and NMR data show that the dihedral angles of PNA/DNA or PNA/DNA complexes are very different from those of DNA:DNA or RNA:RNA complexes. In addition, the PNA strand is very flexible. One way to improve the binding affinity of PNA for DNA/RNA is to design a more pre-organized PNA structure. An effective way to rigidify the PNA strand is to introduce …

Computational Studies On R67 Dihydrofolate Reductase: An Investigation Into Its Unique Binding Patterns, Chuanyin Shi

Theses and Dissertations in Biomedical Sciences

R67 dihydrofolate reductase (R67 DHFR) is a plasmid encoded enzyme which catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THF) using NADPH as a cofactor. R67 DHFR is a homo-tetramer and D2 symmetric. It contains only one active site, which spans the central channel of the enzyme. The active site can bind either two reactants (DHF), two cofactors (NADPH) or one of each (NADPH/DHF), which is the productive ternary complex (i.e. the complex which yields product). In order to favor formation of the productive complex, this enzyme exhibits binding cooperativity. Unlike other allosteric enzymes which achieve binding cooperativity through conformational …