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Autophosphorylation and Autoactivation of an S6/H4 Kinase Isolated From Human Placenta

Description: A number of protein kinases have been shown to undergo autophosphorylation, but few have demonstrated a coordinate increase or decrease in enzymatic activity as a result. Described here is a novel S6 kinase isolated from human placenta which autoactivates through autophosphorylation in vitro. This S6/H4 kinase, purified in an inactive state, was shown to be a protein of Mr of 60,000 as estimated by SDS-PAGE and could catalyze the phosphorylation of the synthetic peptide S6-21, the histone H4, a… more
Date: May 1994
Creator: Dennis, Patrick B. (Patrick Brian)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Stretching the Flexible Myosin II Subfragment Using the Novel Gravitational Force Spectroscope, and the Uncoiling of S2

Description: Familial Hypertrophic cardiomyopathy (HCM) causes ventricle walls to thicken and often leads to sudden death especially in adults. Mutations in the subfragment 2 (S2) of β-cardiac myosin are implicated in the genetic disorder. This S2 region is a coiled-coil rod region resulting from the dimeric form of myosin II. It has been proposed that an elastic quality allows normal S2 to absorb force during the powerstroke according to the sliding filament model. To test the flexibility of single mo… more
Date: May 2010
Creator: Dunn, James W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Hindrance of the Myosin Power Stroke Posed by the Proximity to the Troponin Complex Identified Using a Novel LRET Fluorescent Nanocircuit

Description: A novel luminescence resonance energy transfer (LRET) nanocircuit assay involving a donor and two acceptors in tandem was developed to study the dynamic interaction of skeletal muscle contraction proteins. The donor transmits energy relayed to the acceptors distinguishing myosin subfragment-1 (S1) lever arm orientations. The last acceptor allows the detection of S1's bound near or in between troponin complexes on the thin filament. Additionally, calcium related changes between troponin T and my… more
Date: May 2007
Creator: Coffee Castro-Zena, Pilar G.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Purification, Characterization and Receptor Binding of Human Colony-Stimulating Factor-1

Description: Human colony-stimulating factor-1 (CSF-1) was purified from the serum-free conditioned medium of a human pancreatic carcinoma cell line. The four-step procedure included chromatography on DEAE Sepharose, Con A Sepharose and HPLC on phenyl column and reverse-phase C-3 column. The purity of human CSF-1 was demonstrated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS—PAGE) as a single diffuse band with a molecular weight (Mr) of 42,000-50,000 and was further confirmed by a single … more
Date: May 1987
Creator: Shieh, Jae-Hung
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Studies on Hog Plasma Lecithin:cholesterol Acyltransferase: Isolation and Characterization of the Enzyme

Description: Lecithin:cholesterol acyltransferase (LCAT) was isolated from hog plasma and basic physicochemical properties and functionally important regions were investigated. Approximately one milligram of the enzyme was purified to apparent homogeneity with approximately a 20,000-fold increase in specific activity. In the plasma, hog LCAT was found to associate with high-density lipoproteins (HDL) probably through hydrophobic interactions with apolipoprotein A-I. HDL was the preferred lipoprotein substra… more
Date: May 1987
Creator: Park, Yong Bok
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Mechanism of the Adenosine 3',5'-Monophosphate Dependent Protein Kinase

Description: Isotope partitioning experiments were carried out with the adenosine 3',5'-monophosphate-dependent protein kinase catalytic subunit (cAPK) from bovine hearts to obtain information on the order of addition of reactants and the relative rates of reactant release from enzyme compared to the catalytic step(s). A value of 100% trapping for both ErMgATP-[γ-32P] and E:3H-Serpeptide at low Mgf indicates that MgATP and Serpeptide dissociate slowly from the enzyme compared to the catalytic step(s). The K… more
Date: May 1988
Creator: Kong, Cheng-Te
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Nucleotide Inhibition of Glyoxalase II

Description: The glyoxalase system mediates the conversion of methylglyoxal, a toxic ketoaldehyde, to D-lactic acid. The system is composed of two enzymes, glyoxalase I (Glo-I) and glyoxalase II (Glo-II), and exhibits an absolute requirement for a catalytic quantity of glutathione (GSH). Glo-I catalyzes the isomerization of a hemithioacetal, formed non-enzymatically from methylglyoxal and GSH, to the corresponding a -D-hydroxyacid thioester, s-D-lactoylglutathione (SLG). Glo-II catalyzes the irreversible br… more
Date: May 1999
Creator: Gillis, Glen S
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Conformational Studies of Myosin and Actin with Calibrated Resonance Energy Transfer

Description: Resonance energy transfer was employed to study the conformational changes of actomyosin during ATP hydrolysis. To calibrate the technique, the parameters for resonance energy transfer were defined. With conformational searching algorithms to predict probe orientation, the distances measured by resonance energy transfer are highly consistent with the atomic models, which verified the accuracy and feasibility of resonance energy transfer for structural studies of proteins and oligonucleotides. … more
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Date: May 2000
Creator: Xu, Jin
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Sensitive Microtiter Assays for NAD, NADP and Protein Quantification in Human Lymphocytes

Description: Intracellular levels of NAD are of renewed interest in clinical and basic science research due to the new discovery of enzymes which utilize NAD as a substrate. Microtiter assays for the determination of NAD, NADP and protein were developed as modifications of previously published methods. The resulting assays are simple, cost effective and sensitive. An improved method of isolating lymphocytes was also developed. The resultant procedure requires one hour and removes greater than 99.9% of the p… more
Date: May 1990
Creator: Johnson, James, 1964-
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Studies on ADP-Ribose Polymer Metabolism in Cultured Mammalian Cells Following DNA Damage

Description: ADP-ribose polymer metabolism has been studied in human cells derived from a patient with Glutamyl Ribose Phosphate Storage Disease (GRPSD) and in mouse C3H1OT1/2 cells following oxidative stress induced by hydrogen peroxide (H202 ). It has been postulated that GRPSD resulted from an abnormality in ADP-ribose polymer metabolism. This study has shown that these cells exhibit reduced poly(ADP ribose) polymerase activity which is proposed to result from modification of the enzyme with ribose phosp… more
Date: May 1991
Creator: Maharaj, Geeta
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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The Regulation of HMG-CoA Reductase by Enzyme-Lipid Interactions

Description: The temperature-dependent catalytic activity of rat liver 3-hydroxy-3 -methylglutaryl coenzyme A reductase (HMG-CoA reductase) displays the nonlinear Arrhenius behavior characteristic of many membrane-bound enzymes. A two-conformer equilibrium model has been developed to characterize this behavior. In the model, HMG-CoA reductase undergoes a conformational change from a low specific activity to a high specific activity form. This conformation change is apparently driven by a temperature-depende… more
Date: May 1981
Creator: Smith, Vana L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Homologous Recombination in Q-Beta Rna Bacteriophage

Description: Q-Beta phage RNAs with inactivating insertion (8 base) or deletion (17 base) mutations within their replicase genes were transfected into Escherichia coli spheroplasts containing QB replicase provided in trans by a resident plasmid. Replicase-defective (Rep~) Q3 phage produced by these spheroplasts were unable to form plaques on cells lacking this plasmid. When individual Rep~ phage were isolated and grown to high titer in cells containing plasmid derived Q3 replicase, revertant Q3 phage (Rep')… more
Date: May 1992
Creator: Palasingam, Kampan
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Kinetic and Chemical Mechanism of 6-phosphogluconate Dehydrogenase from Candida Utilis

Description: A complete initial velocity study of the 6-phosphogluconate dehydrogenase from Candida utilis in both reaction directions suggests a rapid equilibrium random kinetic mechanism with dead-end E:NADP:(ribulose 5-phosphate) and E:NADPH:(6- phosphogluconate) complexes. Initial velocity studies obtained as a function of pH and using NAD as the dinucleotide substrate for the reaction suggest that the 2'-phosphate is critical for productive binding of the dinucleotide substrate. Primary deuterium isoto… more
Date: May 1993
Creator: Berdis, Anthony J. (Anthony Joseph)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Characterization of a Human 28S Ribosomal RNA Retropseudogene and Other Repetitive DNA Sequence Elements Isolated from a Human X Chromosome-Specific Library

Description: Three genomic clones encompassing human DNA segments (designated LhX-3, LhX-4, and LhX5) were isolated from an X chromosome-specific library and subjected to analysis by physical mapping and DNA sequencing. It was found that these three clones are very rich in repetitive DNA sequence elements and retropseudogenes.
Date: May 1994
Creator: Wang, Suyue
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Identification of Endogenous Substrates for ADP-Ribosylation in Rat Liver

Description: Bacterial toxins have been shown to modify animal cell proteins in vivo with ADPR. Animal cells also contain endogenous enzymes that can modify proteins. Indirect evidence for the existence in vivo of rat liver proteins modified by ADPR on arginine residues has been reported previously. Presented here is direct evidence for the existence of ADP-ribosylarginine in rat liver proteins. Proteins were subjected to exhaustive protease digestion and ADP-ribosyl amino acids were isolated by boronate ch… more
Date: May 1992
Creator: Loflin, Paul T. (Paul Tracey)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Identification and quantification of lipid metabolites in cotton fibers: Reconciliation with metabolic pathway predictions from DNA databases.

Description: The lipid composition of cotton (Gossypium hirsutum, L) fibers was determined. Fatty acid profiles revealed that linolenate and palmitate were the most abundant fatty acids present in fiber cells. Phosphatidylcholine was the predominant lipid class in fiber cells, while phosphatidylethanolamine, phosphatidylinositol and digalactosyldiacylglycerol were also prevalent. An unusually high amount of phosphatidic acid was observed in frozen cotton fibers. Phospholipase D activity assays revealed that… more
Date: May 2004
Creator: Wanjie, Sylvia W.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Studies on actomyosin crossbridge flexibility using a new single molecule assay.

Description: Several key flexure sites exist in the muscle crossbridge including the actomyosin binding site which play important roles in the actomyosin crossbridge cycle. To distinguish between these sources of flexibility, a new single molecule assay was developed to observe the swiveling of rod about a single myosin. Myosins attached through a single crossbridge displayed mostly similar torsional characteristics compared to myosins attached through two crossbridges, which indicates that most of the tors… more
Date: May 2004
Creator: Gundapaneni, Deepika
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Molecular and biochemical characterization of phospholipase D in cotton (Gossypium hirsutum L) seedlings.

Description: N-Acylethanolamines (NAEs) are enriched in seed-derived tissues and are believed to be formed from the membrane phospholipid, N-acylphosphatidylethanolamine (NAPE) via the action of phospholipase D (PLD). In an effort to identify a functional NAPE-PLD in cotton seeds and seedlings, we have screened a cotton seedling cDNA (cotyledon mRNA from 48 h dark grown seedlings) library with a 1.2 kb tobacco partial cDNA fragment encoding the middle third of a putative PLDβ/γ (genbank accession, AF195614)… more
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Date: May 2005
Creator: McHugh, John
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Identification and Characterization of a Calcium/Phospholipid-Dependent Protein Kinase in P1798 Lymphosarcomas

Description: Calcium/phospholipid-dependent protein kinase (PKC) was partially purified from P1798 lymphosarcoma. Phospholipid-dependence was specific for phosphatidylserine. PKC phosphorylated Histone 1, with an apparent K_m of 14.1 μM. Chlorpromazine, a lipid-binding drug, inhibited PKC activity by 100%. Further studies were undertaken to establish analytical conditions which could be applied to the study of PKC in intact cells. The conditions included (1) determining optimum cell concentration for measur… more
Date: May 1984
Creator: Magnino, Peggy E. (Peggy Elizabeth)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Studies on Lipoprotein Specificity of Human Plasma Lecithin Cholesterol Acyltransferase

Description: Huian plasma high-density lipoprotein (HDL) were isolated by a procedure employing polyanion precipitation and column chromatography. Lipid and protein composition of the HDL isolated by this method was found to be similar to another HDL preparation isolated by ultracentrifugation. However, minor differences were noted, including a higher phospholipid and apoproteinE content and lower triglyceride content of the HDL isolated by column chromatography. Four subfraction of HDL were obtained follow… more
Date: May 1981
Creator: Jahani, Mehrnoosh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Brainstem Gangliosides in Suddden Infant Death Syndrome

Description: Recent studies have shown that the Sudden Infant Death Syndrome (SIDS) is related to abnormal control of respiration (Ischemic degeneration of the brainstem may play an important role in altered respiratory control leading to death). In our studies we have examined brainstem ganglioside compositions in samples derived from SIDS victims and appropriate controls. Gangliosides are acidic glycosphingolipids that contain sialic acid. The high concentration of gangliosides in the central nervous syst… more
Date: May 1987
Creator: Khorsandi, Mehdi
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Purification and Studies of Methylglyoxal Reductase from Sheep Liver

Description: The objectives of these investigations were (1) the purification of MG reductase from sheep liver and (2) studies of some of its characteristics. MG reductase was purified 40 fold and showed a single band on SDS-PAGE. Molecular weight estimations with SDS-PAGE showed a molecular weight of 44,000; although gel filtration with Sephadex G-150 gave a molecular weight of 87,000 indicating that the enzyme might be a dimer. The Km for MG is 1.42 mM and for NADH it is 0.04 mM. The pH optimum for the pu… more
Date: May 1983
Creator: Lambert, Patricia A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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