Biochemistry, Biophysics, and Structural Biology Commons^™

A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

N-Nitrosamines and N-nitrosamides have been reported to be mutagenic. N-Nitrosamides are direct mutagens that need no activation to be mutagenic, whereas N-nitrosamines need to be enzymatically activated to exert their mutagenicity. Oxidative demethylation of nitrosamines is a commonly accepted activation mechanism. Another pathway of nitroso compounds, denitrosation, has recently been proposed. The mechanism of denitrosation, however, is still unknown.

The purpose of this study was to use a photo -reaction model to explore the possible denitrosation mechanism of N-nitroso compounds. An N-nitrosamine, N-nitrosomorpholi ne (NMOR), and an N-nitrosamide, N-methyl-N'-nitrosoguanidine (MMNG), were irradiated with long-wavelength UV light in the presence of …

Identification Of A Variant Form Of The Human Estrogen Receptor With An Amino Acid Replacement, T. Garcia, M. Sanchez, J. L. Cox, P. A. Shaw, J. B. A. Ross, S. Lehrer, B. Schachter

Chemistry and Biochemistry Faculty Publications

Estrogen receptor (ER) is a ligand-dependent transcriptional regulator. ER protein has several functionally distinct regions, including a DNA-binding domain in its midportion, a ligand binding domain in the carboxy terminal region, and at least one domain, in the amino terminal region, that influences the magnitude of transcriptional enhancement (1,2). We now report the sequence of a frequently occurring ER genetic variant that carries two point mutations in the region of the gene encoding the amino terminal domain of the protein.

The Synthesis And Evaluation Of 5-Phenyloxazolidines As Potential Cardiovascular Drugs, Tammy C. Wang

Chemistry & Biochemistry Theses & Dissertations

Drugs such as adrenoceptor antagonists and certain centrally acting agents are known to lower blood pressure and thus serve as clinically useful antihypertensive agents. Norepinephrine 4, a natural ∝-adrenoceptor agonist, is the major agent associated with increased blood pressure in the periphery. Based on a careful structure-activity comparison, a series of substituted oxazolidines, 20, 21, 22 and 23, have been designed as possible antihypertensive candidates. Specifically, 22 and 23 have been synthesized to serve as potential norepinephrine antagonists.

Preliminary evaluation of these compounds indicated that they were not antihypertensive in nature. The more active compound, 23, …

Reactions Of Aqueous Chlorine In The Gastric Fluid Of The Rat, Michael Gary Nickelsen

Chemistry & Biochemistry Theses & Dissertations

Gastric fluid was recovered from Sprague-Dawley rats that had been fasted for 24 hr or 48 hr and administered 4 mL deionized water. The protein, carbohydrate and chloride ion content of the gastric fluid was determined.

When gastric fluid is chlorinated with radiolabeled chlorine to concentrations between 323 and 375 mg/L, analyzed by high performance chromatography followed by liquid scintillation counting, as much as 59% of the radiolabeled chlorine was associated with organic components of the gastric fluid.

Model studies with the aromatic amino acids and the protein pepsin showed the formation of chlorinated analogs. Two chlorinated amino acid derivatives …

Use Of 52Cr For The Quantitative Determination Of Red Cell Volume, Claude Michael Hanbury

Chemistry & Biochemistry Theses & Dissertations

Chromium-52 has recently been suggested for use as a new agent to label red cells for the in vivo quantitation of red cell volume (1). In this paper, the development and validation of a routine ⁵²cr labeling procedure is described.

The accuracy, precision, and detection limits of chromium analysis by Zeeman effect atomic absorption spectroscopy was evaluated in the concentration range of 1 - 10 ug Cr/L.

Red cell chromium uptake was evaluated as a function of time, temperature, and concentration. Red cells labeled with a 2.5 mg/L chromium solution for 30 minutes at room temperature exhibited optimal label …

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.

Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick

Faculty Publications, Biological Sciences

We have examined the nuclear localization of isoprenylated proteins in CHO-K1 cells labeled with [14C]mevalonate. Nuclear proteins of 68, 70, and 74 kD, posttranslationally modified by an isoprenoid, are also components of a nuclear matrix-intermediate filament preparation from CHO cells. Furthermore, the 68-, 70-, and 74-kD isoprenylated polypeptides are immunoprecipitated from cell extracts with two different anti-lamin antisera. Based on exact two-dimensional comigration with lamin B, both from rat liver lamin and CHO nuclear matrix-intermediate filament preparations, and its immunoprecipitation with anti-lamin antisera, we conclude that the 68-kD isoprenylated protein found in nuclei from [14C]mevalonate-labeled CHO cells is lamin B. …

Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis

Chemistry & Biochemistry Theses & Dissertations

Duplex formation between oligo(C:G) _n where n=3 to 4 was shown not to occur under conditions favorable for duplex formation between poly G and poly C. Instead, a stable guano sine self-structure was found to form which a T_m of 50°C for (Gp)₃ and 80°C for (Gp)₄ at strand concentrations of 10^-5M in 1M NaCl. Neither a duplex nor a self-structure formed in the absence of salt.

Oligomers of guanosine and cytosine were obtained by basic hydrolysis and separated according to chain length using DEAE Sephadex column chromatography. Separation of cytosine oligomers with chain lengths …

Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler

Publications (WR)

Ninety-three wildlife agencies were surveyed for information on their attempts to improve fish habitat. In addition, an annotated bibliography including over 100 summaries was completed on: 1. largemouth bass cover requirements and preferences, 2. use and effectiveness of artificial cover, 3. aquatic plant introduction and species requirements for germination and establishment, 4. terrestrial plant introduction and species requirements for germination and establishment, and 5. nutrient exchange between sediment, aquatic plants, and water. A reconnaissance of existing terrestrial and aquatic vegetation was completed in June 1986 including the production of a video tape of the Nevada shoreline of Lake Mead. Cover …

Synthesis Of Potential Long Acting Calcium Channel Antagonists: A Study Of 1,4-Dihydropyridine Analogs, Thomas E. Christos

Chemistry & Biochemistry Theses & Dissertations

An investigation was undertaken to synthesize and evaluate longer acting analogs to the antihypertensive agent nifedipine. Analogs that are capable of covalent bonding to the nifedipine receptor were considered. These compounds may show increased activity as they will remain at the receptor for a longer period of time.

During the course of this study, previously unreported and unexpected products were encountered and lead to a more intense examination of the Hantzsch synthesis. Of particular interest was the oxazolidine 25 which was a major component of the Hantzsch synthesis when ethanolamine was used instead of ammonium hydroxide. Also isolated during this …

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.

Raw Nutrient Data, Leanna Gail

Publications (WR)

Data collected at various stations around Lake Mead. Includes information about substances present in various water samples.

The Synthesis And Evaluation Of The Cardiovascular Activity Of Novel Imidazole Ring Systems, Joseph E. De Los Angeles

Chemistry & Biochemistry Theses & Dissertations

An investigation was undertaken to synthesize and evaluate the cardiovascular activity of two imidazole ring systems. Imidazoles with hypotensive activity would provide novel potential antihypertensive drugs. These novel structures may also find use as chemical probes in the study of the cardiovascular system and as prototypes for other potential cardiovascular agents.

The histamine derivative, 7,7-dipyridyl-4,5,6,7-tetrahydroimidazo-[4,5-c]pyridine (ligand l), was demonstrated to possess significant hypotensive activity in laboratory rats. A 15 mg/Kg dose of ligand 1 produces a statistically significant decrease in blood pressure when injected IP. This hypotensive effect is also associated with marked increase in heart rate. Although compound 1 …

Mössbauer Spectroscopic Studies Of Hemoglobin And Its Isolated Subunits, G. R. Hoy, D. C. Cook, R. L. Berger, F. K. Friedman

Physics Faculty Publications

Samples of 90% enriched ⁵⁷Fe hemoglobin and its isolated subunits have been prepared. Mössbauer spectroscopic measurements have been made on three such samples. Sample one contained contributions of oxyhemoglobin, deoxyhemoglobin, and carbonmonoxyhemoglobin. This sample was studied from a temperature of 90 K down to 230 mK. Measurements were also made at 4.2 K using a small applied magnetic field of 1.0 T. In general, the measured quadrupole splittings and isomer shifts for each component agreed with previous measurements on single component samples in the literature, and thus demonstrated that chemically enriched hemoglobin has not been altered. The second and …

Magnesium, Copper And Zinc Concentrations In Blood From Children With Diabetes Mellitus, Linda Lowers Jenkins

Chemistry & Biochemistry Theses & Dissertations

Trace element levels in blood from diabetic children were investigated and compared to control children. Plasma, erythrocyte, mononuclear and polymorphonuclear cells were analyzed for magnesium, copper, and zinc content. Leukocyte separation was performed by density gradient centrifugation on Ficoll-Hypaque, followed by washing steps to remove platelet contamination and hypotonic lysis to remove red cell contamination. Polarized Zeeman-effect atomic absorption spectroscopy was used for trace metal analysis.

Decreased plasma magnesium levels were observed in the diabetic children. This finding is well documented and probably due to increased urinary magnesium loss from glycosuria. Lymphocyte magnesium levels in the diabetic children were also …

Photoaffinity Labeling Of The Antimycin Binding Site In Rhodopseudomonas Sphaeroides, Emily Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to identify the site of interaction of antimycin with the ubiquinone-cytochrome b-c1 oxidoreductase in the photosynthetic bacteria, Rhodopseudomonas sphaeroides. To accomplish this goal, three areas of research were undertaken: the synthesis of a radiolabeled, photoaffinity analog of antimycin, identification of the inhibitory characteristics of this analog, and the photoaffinity labeling of the antimycin binding site. All three areas were accomplished.

The major finding of this study was the identification of an 11,000 dalton polypeptide as the predominantly labeled protein. Although this polypeptide was not exclusively labeled, it was consistently labeled and showed competition …

The Synthesis Of Various Substituted 3-Amino-7-Hydroxy-2,2-Dimethyltetralins And Their Opioid-Related Activities, David Alan Lippman

University of the Pacific Theses and Dissertations

A series of aminotetralones and aminotetralins were synthesized from the common intermediate F, 3-amino-2,2-dimethyl-7-methoxy- 1-tetralone. The final compounds derived from F were simple substituted and/or reduced analogues. The products would allow a progressive structure activity relationship to be drawn based on pharmacological testing.

The common intermediate F was synthesized utilizing a six step procedure starting with p-methoxyphenylacetic acid. The overall yield from the precursor to the F:HC1 was 25%. Compound F was either O-demethylated to form 3-amino-2,2-dimethyl-7-hydroxy-l-tetralone (I) or was dimethylated on the amine and subsequently O-demethylated to yield the 3-dimethylamino-7-hydroxy-2,2-dimethyl-l-tetralone (J). The last major modification was the reduction of …

Determination Of N,N'-Diphenylguanidine In Biological Tissues And Fluids Using High Pressure Liquid Chromatography, Edward Sidney Hunter Iii

Chemistry & Biochemistry Theses & Dissertations

N,N'-Diphenylguanidine (DPG) is a potentially toxic compound used in the vulcanization of rubber products. Distribution of DPG in hybrid mice (C57BL/6J interbred with DAB₂) was determined following intraperitoneal injection. Urine, fecal material, whole blood and tissues were collected at various times after administration of DPG and the extracts analyzed for DPG by high pressure liquid chromatography. Recovery of DPG from spiked urine and whole blood exceed 90%, however, the recovery of DPG from spiked tissue samples was approximately 70%.

DPG concentration in whole blood reached a maximum within ten minutes and rapidly decreased through 180 minutes after administration …

Analysis Of The Surface Polysaccharides Of R. Trifolii Su843 And Its Sym Plasmid Alterated Mutants, Jauh-Lin Duh

Masters Theses

The Rhizobium trifolii polysaccharides from SU843 and mutants--HC843(pBR1AN), HC843, 8002--in which the sym plasmid is replaced, absent, or mutated by transposon Tn5 were isolated. The surface polysaccharides of genetically altered mutants were compared quantitatively and qualitatively with one another and with the parent strain. The interpretation of these results is discussed in relation to the function of Rhizobium surface polysaccharides in the symbiotic process. The symbiotic ability of SU843 and mutant strains is as follows: (a) SU843, nod⁺, fix⁺; (b) mutant 8002, roa⁺ (still attaches to root hair), hac^-, nod^-; (c) …

Spermidine-Condensed Phi X174 Dna Cleavage By Micrococcal Nuclease: Torus Cleavage Model And Evidence For Unidirectional Circumferential Dna Wrapping., Kenneth A. Marx, Thomas C. Reynolds

Dartmouth Scholarship

Spermidine-condensed phi X174 replicative form (RF) II DNA was digested with micrococcal nuclease to yield seven identifiable DNA bands forming an arithmetic fragment-length series. The DNA monomer unit length was found to be 780 +/- 80 base pairs. This result is most consistent with a proposed model for micrococcal nuclease cleavage of a DNA torus organized by the unidirectional, circumferential wrapping of B-geometry DNA. By a topological consideration, the blunt-end-rod-fusion model for torus formation [Eickbush, T. H. & Moudrianakis, E. N. (1978) Cell 13, 295-306] is shown to be inconsistent with our empirical solution results. We propose a continuous, circumferential …

Development Of An On-Line Computer System For Enzyme Kinetics Studies, Jacqueline R. Thweatt

Chemistry & Biochemistry Theses & Dissertations

The PDP-11/10 minicomputer was interfaced to the Beckman 25 ultraviolet/visible spectrophotometer and this on-line computer system was applied to enzyme kinetics studies. This interface involved hardware equipment to locate, amplify, and transmit the analog signal to an analog-to-digital converter, and software to acquire and store the digital data. Data processing programs were used to calculate kinetic parameters and statistical information from the acquired data.

The Varian Cary 219 ultraviolet/visible spectrophotometer can be readily interfaced to the Apple II Plus microcomputer by hardware equipment which can be purchased from the manufacturer. Various software may also be purchased for use in enzyme …

Ortho Cyclization Reactions Of Catecholamines, Robert Lee Hudkins

Chemistry & Biochemistry Theses & Dissertations

A study was undertaken to examine the potential for ortho cyclization associated with the synthesis of 1,2,3,4,-tetrahydroisoquinolines using the Pictet-Spengler reaction. Specif1cally, the condensation of the biogenic amines, dopamine, norepinephrine and epinephrine were carefully examined in light of current literature and the facility and extent of ortho cyclization in each case. The para isomers of these three biogenic amine condensation products were isolated and characterized, while only the ortho isomer derived from dopamine was found stable and could be isolated, and structurally identified. These studies demonstrate that a second cyclization product does, in fact, form in each instance and that …

High-Temperature Battery Calorimeter, L. D. Hansen, R. H. Hart, D. M. Chen, H. F. Gibbard

Faculty Publications

A battery calorimeter was built for the measurement of thermal energy generation of high-temperature lithium–aluminum/iron sulfide battery cells, which are under development for electric vehicle propulsion and other energy storage applications. The calorimeter was designed with a temperature range of 400˚–500˚C, a detection limit of 1 mW, and an upper limit of heat flow of 50 W. The results of measurements on 200-Ah LiAl/FeS cells were in excellent agreement with the predictions of thermodynamic calculations based on precise measurements of the total cell polarization and the temperature coefficient of the emf. Details of the construction and operation principles of this …

Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong

Chemistry & Biochemistry Faculty Publications

The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies of N-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation …

The Transport And Intracellular Distribution Of Iron In The Basidiomycete, Ustilago Sphaerogena, Charles W. Passavant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The transport and intracellular distribution of iron in Ustilago sphaerogena via the native siderochrome ferrichrome A has been examined. Evidence is presented which suggests the involvement of deferriferrichrome in iron transport when the metal is supplied to the cell as ferrichrome A. This process requires both oxygen and ATP synthesis and may require a transmembrane electrochemical gradient. Once inside the cell, iron derived from ferrichrome A is rapidly distributed, with a major fraction found in the mitochondria, presumably as heme.

The kinetics of ferrichrome and ferrichrome A uptake have also been investigated. The Km of transport of ferrichrome was …

High Performance Liquid Chromatographic Analysis Of Biogenic Amines, Thais Edwina Ahrendt Keegan

Chemistry & Biochemistry Theses & Dissertations

The objectives of this research were to develop a sensitive method for separation and quantitation of biogenic amines and to apply that procedure by monitoring neurochemical changes resulting from stimuli to the test system.

Primary aromatic amines were derivatized with o-phthalaldehyde-mercaptoethanol prior to chromatography, Separation of the fluorescent adduct was achieved using a μBondapak/ phenyl reversed-phase column and a two-step gradient of methanol:0.08 M acetic acid, pH J.O. Fluorescence was monitored using a J40 nm excitation energy and an emission filter which transmits radiation greater than 400 nm (50% T at 418 nanometers).

Following optimization of the chromatographic conditions, studies …

Studies Of The Reorientational Relaxation Of Pyridine In Water By Depolarized Rayleigh Light Scattering, C. H. Wang, Scott L. Whittenburg, P. A. Lund, D. H. Christensen

Chemistry and Biochemistry Faculty Publications

The depolarized Rayleigh spectra of aqueous solutions of pyridine have been studied using a high‐finesse Fabry–Perot interferometer as a function of temperature and concentration. The Rayleigh relaxation times are found to have a complex concentration and viscosity dependence. The classical Stokes–Einstein–Debye equation for molecular reorientation breaks down in this system. The Rayleigh relaxation time of pyridine molecules is not determined by the macroscopic shear viscosity of the solution. The specific interaction due to the formation of hydrogen bonds between pyridine and water molecules plays a very important role in affecting the relaxation time. At a fixed temperature the plot of …

Adaptative Alteration In Phospholipid Composition Of Plasma Membranes From A Somatic Cell Mutant Defective In The Regulation Of Cholesterol Biosynthesis, Michael Sinensky

Faculty Publications, Biological Sciences

A somatic cell mutant (CR1) of a Chinese hamster ovary cell (CHO-K1) which has previously been shown to be defective in the regulation of cholesterol biosynthesis accumulates more cholesterol than the parental cell line in plasma membranes. Although such an increase in membrane cholesterol should lead to an increase in the order parameter of these membranes, as measured with an electron spin resonance spin probe, the order parameters of mutant and wild-type plasma membranes are identical--apparently because of an adaptive alteration in membrane phospholipid composition. The phospholipid compositions of mutant and wild-type cell plasma membranes are compared and the mutant …

The Association Of 5.8 S With 28s Ribosomal Rna, Nandita Banerjee

Chemistry & Biochemistry Theses & Dissertations

5.8S rRNA is a low molecular weight ribosomal RNA which is noncovalently bonded to the larger ribosomal subunit 28S rRNA; through its 3' end and through its 5' end. This interaction is an integral part of the ribosome, and plays an important role in the ribosome structure and function.

There is a high degree of homology between the 5.8S rRNA primary structures of rat, turtle and chicken. The base sequence of rat 5.8S rRNA differs only in one position from that of turtle and in three positions fr.om that of cl1.icken. Tl1ere is a single purine substitution at the 5' …

Heating-Effect Minimization In Dye Lasers, Kenneth Lee Matheson, James M. Thorne

Faculty Publications

Optical pumping of dye lasers deposits heat nonuniformly in the active medium. Because the refractive index of a liquid or gas is a function of temperature, gradients are created which refract the laser beam. This effect is sometimes serious enough to quench laser action. In this paper, we evaluate the effects caused by optical pumping with a coaxial flashlamp and suggest ultraviolet absorbers and wavelength shifters as materials for minimizing the problem