Biochemistry, Biophysics, and Structural Biology Commons^™

Structural Characterization Of A Novel Inhibitor Of Hiv Reverse Transcriptase (Hiv Rt), Greggory Jon Woitte

Chemistry & Biochemistry Theses & Dissertations

Human immunodeficiency virus (HIV) infections have become a leading cause of death among young people in the United States today. As the number of HIV infections increases, so too does the cost of treatment. Together, these numbers have prompted an increase in the development of pharmaceutical interventions. HIV reverse transcriptase (HIV RT) has become a suitable target for drug therapy because it is the sole enzyme responsible for HIV replication.

Fucoidan, a sulfated polysaccharide isolated from the brown algae Fucus vesiculosus, has been shown to block a variety of cell adhesion related events including metastasis. In addition, fucoidan has also …

A Kinetic Investigation Of The Mechanism Of Muscle Contraction With A Series Of Nucleotides, Wei Jiang

Theses and Dissertations in Biomedical Sciences

Muscle contraction is thought to be accomplished by sliding of myosin filaments along actin filaments. Although actomyosin naturally uses ATP as an energy source, it can also use other nucleoside triphosphates (NTP) as substrates. In this work, the dependence of rate and equilibrium constants of the various steps in the muscle contraction mechanism upon nucleotide structure was investigated to unravel the dependence of the mechanical properties of the muscle upon changes in different biochemical steps of the mechanism.

The experiments measuring the dissociation of actomyosin by NTP (or mant-NTP) shows that both the rate constant of actomyosin-S1 dissociation and second …

Restoration Of Circadian Behavior By Anterior Hypothalamic Heterografts, Patricia J. Sollars, Daniel P. Kimble, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) of the anterior hypothalamus (AH) is a circadian oscillator and an important component of the mammalian circadian system. To determine whether the SCN is the dominant circadian pacemaker responsible for generating a species-typical characteristic of circadian rhythms [i.e., period length (T)], neural transplantation was conducted using fetal AH donors of different species and SCN-lesioned (SCNx) hosts. The circadian behavior of each of the three donor species is clearly distinguishable by its species-typical T. The extent of SCN pacemaker autonomy was assessed by noting whether the period of the restored circadian rhythm following heterograft transplantation was characteristic …

Biotransformation Of Bile Acids, Cholesterol And Steroids. Chapter 13 In: The Ecology And Physiology Of Gastrointestinal Microbes. Vol. 1, New York, Chapman And Hall., Stephen Baron, Phillip B. Hylemon

Biology Faculty Scholarship

No abstract provided.

Certain Canine Weakly Β-Hemolytic Intestinal Spirochetes Are Phenotypically And Genotypically Related To Spirochetes Associated With Human And Porcine Intestinal Spirochetosis, Gerald E. Duhamel, Nagaraja Muniappa, Michelle R. Mathiesen, J. L. Johnson, J. Toth, R. O. Elder, A. R. Doster

School of Veterinary and Biomedical Sciences: Faculty Publications

Four canine weakly β-hemolytic intestinal spirochetes associated with intestinal spirochetosis (IS-associated WBHIS) were compared with IS-associated human and porcine WBHIS and the type species for Serpulina hyodysenteriae and S. innocens by using phenotypic and genotypic parameters. The IS-associated canine, human, and porcine WBHIS belonged to a phyletic group distinct from but related to previously described Serpulina type species.

A Study Of Euplotes Crassus Telomere Proteins And Related Genes, John Scott Perez

Department of Chemistry: Dissertations, Theses, and Student Research

A novel PCR technique used to amplify Euplotes crassus macronuclear chromosomes was developed to provide scientific proof that an Euplotes crassus 1.0 kb gene is not genetically related to an Oxytricha nova 1.8 kb β-telomere protein gene. Theories and experimental procedures associated with the development of this PCR technique were the product of research that will have a profound impact on future studies of telomere protein genes and telomeric DNA in a multitude of eukaryotic cells. The hypothesis that a β-telomere protein does not exist in Euplotes crassus was supported by the result of this study.

Expression of the recombinant …

Determination Of Pancreatic And Salivary Amylase By Enzyme Immunoassay And Their Prevalence In Hyperamylasemic Patients, Sabdra Borgens Ward

Theses and Dissertations in Biomedical Sciences

Currently, amylase determinations are nonspecific for the organ source and are based entirely on the enzymatic properties of amylase to produce a measurable product or byproduct. The determination of pancreatic amylase is important in the diagnosis of acute pancreatitis. Most commercially available tests for amylase employ the measurement of the change in NADH absorbance at 280 nm or of the p-nitrophenol released from a maltotetrose substrate. These are nonspecific measurements of pancreatic amylase and often necessitate other tests to be run such as a serum lipase.

The two predominant isoenzymes of amylase are pancreatic (p-amylase) and salivary (s-amylase); the most …

Signal Transduction In Bacterial Chemotaxis, Edward Heath Rowsell

Loma Linda University Electronic Theses, Dissertations & Projects

This study investigated the site of ATP utilization in the signal transduction pathway of bacterial chemotaxis and localized the point of convergence of a methylation-independent system of chemotaxis with the methylation-dependent system. The identity of the signal originating from the phosphotransferase system was investigated by substituting the fructose-inducible HPr-like protein FPr for HPr in transport and chemotaxis. In addition, a novel chemoattractant, glycerol, was identified for Salmonella typhimurium. Histidine-auxotrophic S. typhimurium strains ST23 (hisF) and ST171 (hisF cheB) were depleted for ATP. The times required for the bacteria to adapt to a step increase in serine, …

Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen

Electronic Theses and Dissertations

Although tachykinins have potent vascular actions, their effect on renal resistance blood vessels is currently unknown. The vasoactive properties of tachykinins and related analogs were assessed in isolated perfused rat kidney. At a basal perfusion pressure (PP) of 75 $\pm$ 6 mm Hg (n = 5), bolus injections of substance P (SP) had no significant vasoactive effect. Following a sustained increase in baseline PP (134 $\pm$ 10 mm Hg) produced by phenylephrine (1 $\mu$M), SP evoked a dose-dependent increase in PP. The largest dose of SP increased PP by 60 $\pm$ 5 mm Hg. The vasoconstrictor response to SP was …

Investigation Of Selenium Status In Hypo-, Hyper- And Euthyroid Children, Ping Sun

Chemistry & Biochemistry Theses & Dissertations

Recently, it has been reported that human type I iodothyronine deiodinase, an enzyme important in the conversion of T₄ to T₃ , is a selenoenzyme. Several studies have reported alterations in plasma selenium level in hypo- and hyperthyroid patients.

Using polarized Zeeman-effect atomic absorption spectroscopy, we measured selenium, zinc, copper and manganese concentrations in the plasma and/or red blood cells in children with or without thyroid disease being seen at the outpatient clinic at Children's Hospital of the King's Daughters. Children with thyroid disease were subdivided into untreated, treated and nonresponsive groups. Data were analyzed using Student's t-test …

Separate Metabolic Pathways Leading To Dna Fragmentation And Apoptotic Nuclear Chromatin Condensation, D. Sun, Shibo Jiang, Li-Mou Zheng, David M. Ojcius, John Ding-E. Young

All Dugoni School of Dentistry Faculty Articles

Apoptosis is the predominant form of cell death observed in a variety of physiological and pathological conditions such as cancer involution, insect metamorphosis, the development of the immune and nervous systems, and embryogenesis. The typical nuclear changes taking place in apoptotic cells include extensive condensation of chromatin and internucleosomal DNA fragmentation into units of 200 base pairs. However, the mechanisms responsible for both chromatin condensation and DNA fragmentation have yet to be elucidated. In this study, micrococcal nuclease and the divalent cations, Ca2+ and Mg2+, were applied to isolated nuclei in an attempt to reconstitute in vitro the digestion of …

An Analysis Of Mitochondrial Dna In Rett Syndrome And Other Neurodegenerative Disorders, Catherine Erickson Burgess

Theses and Dissertations in Biomedical Sciences

Mitochondrial dysfunction resulting from mutations on mitochondrial DNA (mtDNA) is being recognized in a growing spectrum of diseases. These diseases, resulting from single base mutations, large deletions, or insertions, have been largely neuromuscular in origin. However, as an understanding of the effects of mtDNA mutations progresses, attention is now focusing on neurodegenerative diseases. Rett Syndrome (RS), a progressive neurodegenerative disease with predominantly female cases, demonstrates morphologic mitochondrial changes, mitochondrial enzyme deficiencies and maternal inheritance (characteristic of mtDNA diseases). No investigation of mtDNA involvement has been previously conducted and, to date, no biological marker exists for this disorder.

Our preliminary studies …

Morphometric Analysis Of Enteric Lesions In C3h/Hen Mice Inoculated With Serpulina Hyodysenteriae Serotypes 2 And 4 With Or Without Oral Streptomycin Pretreatment, Jagannatha V. Mysore, Gerald Duhamel

School of Veterinary and Biomedical Sciences: Faculty Publications

The segmental distribution and sequential progression and the role of the indigenous bacterial flora in the development of enteric lesions associated with Serpulina hyodysenteriae infection in laboratory mice have not been defined. We examined the distribution and sequential morphometric changes in the large intestine of mice orally inoculated with S. hyodysenteriae serotypes 2 and 4. To determine the role of colonization resistance conferred by the indigenous bacterial flora, 40 female C3H/HeN mice were administered water alone or water containing 5 mg/mL streptomycin sulfate ad libitum for seven days prior to orogastric inoculation either with S. hyodysenteriae or sterile trypticase soy …

Severe Bone Marrow Suppression In A Patient With Rheumatoid Arthritis On Methotrexate, M P. Iqbal, A A. Ali, A A. Alvi

Department of Biological & Biomedical Sciences

No abstract provided.

Sds Non-Acrylamide Polymeric Gel-Filled Capillary Electrophoresis For Molecular Size Separation Of Protein, Devon Andres

Honors Theses

Sodium dodecyl sulfide (SDS) non-acrylamide gel-filled capillary columns are a new technology being used for analysis and separation of biotechnology-derived proteins. This research was to compare this new technology to the current methods of SDS polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance size-exclusion chromatography (HPSEC). The molecular mass of four different recombinant proteins were determined by two commercialized SDS non-acrylamide gel-filled capillary columns, SDS-PAGE, and HPSEC. The data obtained showed that the SDS non-acrylamide gel-filled capillary columns were compatible with the SDS-PAGE technique for molecular mass determination. HPSEC was shown to be unreliable for molecular weight determination. SDS non-acrylamide gel-filled capillary …

Aerotaxis In Bacillus Subtilis, Laurence Samuel Wong

Loma Linda University Electronic Theses, Dissertations & Projects

B. subtilis, like Escherichia coli and Salmonella typhimurium, responded to a step increase in oxygen concentration by swimming smoothly (~ 35 s duration) and to a decrease in oxygen by tumbling. In a spatial gradient of oxygen in liquid media, a band of cells congregated near the air interface. Aerotaxis required a functioning respiratory chain. Adaptation of B. subtilis, E. coli and S. typhimurium to media containing amino acids requires methylation of receptors/methyl-accepting chemotaxis proteins. Adaptation to oxygen and phosphotransferase sugar substrates in B. subtilis was dependent on methylation, unlike similar adaptation in E. coli and S. typhimurium. …

The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy

Chemistry & Biochemistry Theses & Dissertations

Grape seed extract is being marketed in France for cardiovascular use and skin care. The active constituents of both these drugs are certain polyphenols called procyanidins. A similar seed extract has now been obtained from Virginia Chardonnay grape seeds. Ten of the major components in this extract have been isolated in their pure form by the semi-preparative HPLC separation on a YMC ODS-AQ (Octadecylsilane-AQ) column. The ODS-Aq column has been shown to have a better resolving capacity compared to the Spherisorb ODS (Octadecylsilane) column previously described in the literature. This has been attributed to the ODSAQ support which has both …

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 …

Separation And Quantification Of Queuine-Modified And Unmodified Transfer Rna Isoacceptors, Jorge Miguel Pereira De Oliveira Da Silva Santos

Chemistry & Biochemistry Theses & Dissertations

The discovery of a base-exchange modification in the first position of the anticodon of four transfer RNA (tRNA) isoacceptor families has been shown to be correlated with a decrease in the rate of cell division in several tumorigenic tissues. This fact led to the hypothesis that wobbling in the anticodon might be a control point wich mediates the rate of translation. A suitable method for separation of different tRNA isoacceptor families had to be created in order to generate a means for quantitatively measuring degrees of this base modification in tRNA. Radio labelled amino acids were used to charge tRNA …

Detection Of Serum Antibody Responses In Cattle With Natural Or Experimental Neospora Infections, Patricia Conrad, Karen Sverlow, Mark Anderson, Joan Rowe, Robert Bondurant, Gwen Tuter, Richard Breitmeyer, California Department Of Food And Agriculture, Animal Health Branch, Mark Thurmond, Alex Ardans, J. P. Dubey, Gerarld Duhamel, Bradd Barr

School of Veterinary and Biomedical Sciences: Faculty Publications

Parasite-specific antibody responses were detected using an indirect fluorescent antibody (IFA) test in cattle that were naturally or experimentally infected with Neospora parasites. The test was developed using Neospora tachyzoites isolated from an aborted bovine fetus and grown in bovine cell cultures (isolate BPA1). In all cases, infections were confirmed by the identification of Neospora tachyzoites and/or bradyzoite cysts in fetal or calf tissues using an immunoperoxidase test procedure. Fifty-five naturally infected cows that aborted Neospora-infected fetuses had titers of 320-5,120 at the time of abortion. The titer of 6 cows that were serologically monitored over a prolonged period decreased …

Purification And Ligand Binding Of A Soluble Class I Mhc Molecule Consisting Of The First Three Domains Of H-2kd Fused To B2-Microglobulin Expressed In The Baculovirus/Insect Cell System, Francois Godeau, Immanuel F. Luescher, David M. Ojcius, Cecile Saucier, Estelle Mottez, Lucien Cabanie, Philippe Kourilsky

All Dugoni School of Dentistry Faculty Articles

A recombinant baculovirus encoding a single-chain murine major histocompatibility complex class I molecule in which the first three domains of H-2Kd are fused to beta 2-microglobulin (beta 2-m) via a 15-amino acid linker has been isolated and used to infect lepidopteran cells. A soluble, 391-amino acid single-chain H-2Kd (SC-Kd) molecule of 48 kDa was synthesized and glycosylated in insect cells and could be purified in the absence of detergents by affinity chromatography using the anti-H-2Kd monoclonal antibody SF1.1.1.1. We tested the ability of SC-Kd to bind antigenic peptides using a direct binding assay based on photoaffinity labeling. The photoreactive derivative …

Appearance Of A Methotrexate Binding Plasma Protein During High Dose Methotrexate Therapy, M P. Iqbal, I Malik, N Mehboobali

Department of Biological & Biomedical Sciences

No abstract provided.

Biochemical Investigation Of Gout And Its Familial Incidences, Chin-Ling Hsu

Chemistry & Biochemistry Theses & Dissertations

Gout is a chronic metabolic disorder caused by deposition of uric acid on the joint. It is categorized into two types: primary and secondary. Primary gout is uric acid overproduction, caused by excessive synthesis of the purine precursors. Secondary gout occurs also as the result of overproduction or decreased renal excretion of uric acid resulting from other disease processes or medication.

The two purine bases, hypoxanthine and xanthine, liberated from ribosides by the action of nucleoside phosphorylase, are degraded to uric acid as the final excretory product in the purine degradation pathway. Hypoxanthine and xanthine are the physiological substrates of …

Kinetic Characterization Of A Recombinant C-Terminal Mutant Of Reverse Transcriptase From The Human Immunodeficiency Virus, Thomas S. Heard

Chemistry & Biochemistry Theses & Dissertations

The human immunodeficiency virus (HIV) reverse transcriptase (RT) (EC 2.7.7.49) is the central replication enzyme for HIV. In general, the kinetic mechanism for this and all other polymerases involves the ordered binding of two substrates: a primer-template (PT) followed by a deoxyribonucleoside triphosphate (dNTP). Previous investigations prompted this research when it was discovered that the substrate dNTP, in absence of PT, could protect a recombinant c-terminal mutant HIV-1 RT from inhibition by pyridoxal-5'-monophosphate (PLP), an active-site dNTP inhibitor. In contrast, the non-mutant recombinant HIV-1 RT required both substrates for protection from PLP inhibition. This investigation sought to determine if this …

Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff

Dartmouth Scholarship

The mechanisms involved in retinoic acid (RA)-mediated regulation of the collagenase gene in a rabbit synovial fibroblast cell line (HIG82) were investigated. When HIG82 cells are cotransfected with expression vectors containing cDNAs for retinoic acid receptor (RAR) α1, β2, or γ1 and collagenase promoter-driven CAT reporter constructs, only RAR-γ1 represses basal CAT expression upon RA treatment, while RAR-α1, β2, and γ1 all suppress phorbol-induced CAT expression. Thus, transcriptional regulation of collagenase by RA is mediated by RARs in an RAR-type specific manner. Using mutatlonal and deletional analysis, we find that interaction between elements within 182 bp collagenase promoter plays an …

Improved Recovery Of A Radlolabeled Peptide With An Albumin-Treated Reversed-Phase Hplc Column, David S. Hage, Robert L. Taylor, Pai C. Kao

David Hage Publications

Reversed-phase high-performance liquid chromatography (RP-HPLC) is an important tool in the purification of radiolabeled peptides and proteins for immunoassay. However, for some proteins and peptides it is difficult to achieve reproducible behavior in RP-HPLC because of the low recovery of these compounds. Factors that can be varied to improve recovery include the strength or pH of the mobile phase, the chain length and spacing of groups on the reversed-phase support, and the flow rate or steepness of the elution gradient (1-5). ... In summary, we obtained better recovery and more reproducible chromatographic behavior for labeled 1-34 PTHrP with an albumin-pretreated …

Intact Parathyroid Hormone: Performance And Clinical Utility Of An Automated Assay Based On High-Performance Immunoaffinity Chromatography And Chemiluminescence Detection, David S. Hage, Bob Taylor, Pai C. Kao

David Hage Publications

The performance and clinical utility of an automated assay of intact parathyroid hormone (parathyrin, PTH) are evaluated. The method is based on the extraction of PTH from plasma by an HPLC column containing immobilized anti-(44-68 PTH) antibodies. The PTH retained is detected with a postcolumn reactor and use of anti-(1--34 PTH) chemiluminescent-labeled antibodies. The total cycle time of the assay is 6.5 mm per injection after a 1-h incubation.The lower limit of detection for PTH in a 66-pL plasma sample was 0.5 pmol/L based on peak heights and 0.2 pmol/L based on peak areas. Mean analytical recovery for PTH added …

High Performance Liquid Chromatographic Separation Of Different Types Of Collagen, Yongjoo Chung

Chemistry & Biochemistry Theses & Dissertations

The objective of this research was to develop a method for the separation of different types of collagen using a large pore size (100 nm) reversed-phase C-8 column. Three different types of collagen (type I, III, and V) were sufficiently separated on the column using a mobile phase containing water-acetonitrile-trifluoroacetic acid. Collagens found in each HPLC peak were identified using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to assay the column effluents.

Trifluoroacetic acid (TFA) was used as an ion pair reagent. This compound improved the chromatographic profile for these proteins on a reversed-phase column. It was observed that with …

Heterogeneity Of Methotrexate Binding In Human Colon Tumor Cells, M P. Iqbal, N Mehboobali, M A. Waqar, M Ahmed

Department of Biological & Biomedical Sciences

[3H]-methotrexate binding at pH 5.0 and pH 7.2 by the cytosol of tumor tissues and the surrounding normal areas of the gastrointestinal tract of patients suffering from colon or gastric cancer has been used to identify in these cells the presence of a binder of methotrexate having low-affinity for this drug in addition to the enzyme dihydrofolate reductase. Scatchard analysis of the [3H]-methotrexate binding data by a colon tumor sample also reveals that there are two binders of this drug present in the cytosol of these cells. The association constant (Kass) for one binder of methotrexate is = 5.6 x …

Cytolytic And Ion Channel Forming Properties Of The N-Terminus Of Lymphocyte Perforin, David M. Ojcius, Pedro M. Persechini, Li-Mou Zheng, Paulo C. Notaroberto, Sandro C. Adeodato, John Ding-E. Young

All Dugoni School of Dentistry Faculty Articles

Perforin lyses cells by binding to the target cell membrane, where it polymerizes into large nonspecific pores. It is shown here that the first 34 amino acids of the N-terminal region of either human or murine perforin are soluble in aqueous medium and spontaneously insert into membranes. The N-terminal peptides lyse liposomes and nucleated cells, and they form ion channels in planar bilayers, some of which are comparable to those previously described for perforin. The lytic activity of the N-terminal domains does not require calcium, is independent of the lipid headgroup composition, and can be inhibited by heparin. Tumor cells …