Life Sciences Commons^™

In Vivo Regulation Of Wheat-Leaf Phosphoenolpyruvate Carboxylase By Reversible Phosphorylation, Stephen M. G. Duff, Raymond Chollet

Department of Biochemistry: Faculty Publications

Regulation of C₃ phosphoenolpyruvate carboxylase (PEPC) and its protein-serine/threonine kinase (PEPC-PK) was studied in wheat (Trificum aesfivum) leaves that were excised from low-N-grown seedlings and subsequently illuminated and/or supplied with 40 mM KNO₃. The apparent phosphorylation status of PEPC was assessed by its sensitivity to i-malate inhibition at suboptimal assay conditions, and the activity state of PEPC-PK was determined by the in vitro ³²P labeling of purified maize dephospho-PEPC by [y³²PIATP/ Mg. lllumination (±NO₃^-) for 1 h led to about a 4.5-fold increase in the 50% inhibition constant for i-malate, which …

Dephosphorylation Of The Thylakoid Membrane Light-Harvesting Complex-Ii By A Stromal Protein Phosphatase, Mark E. Hammer, Gautam Sarath, John Markwell

Gautam Sarath Publications

Light-harvesting complex-II (LHC-II) phosphatase activity has generally been examined in the intact thylakoid membrane. A recent report of peptide-phosphatase activity associated with the chloroplast stromal fraction (Hammer, M.E et al. (1995) Photosynth Res 44:107–115) has led to the question of whether this activity is capable of dephosphorylating membrane-bound LHC-II. To this end, heat-treated thylakoid membranes were examined as a potential LHC-II phosphatase substrate. Following incubation of the thylakoid membrane at 60 °C for 15 min, the endogenous protein phosphatase and kinase activities were almost eliminated. Heat-inactivated phosphomembranes exhibited minimal dephosphorylation of the light harvesting complex-II. Peptide-phosphatase activities isolated from the …

Molecular Cloning And Rare Cleavage Mapping Of Human 2p, 6q, 8q, 12q, And 18q Telomeres, Roberto A. Macina, Ken Morii, Xue-Lan Hu, Dimitri G. Negorev, Chrysanthe Spais, Lisa A. Ruthig, Harold C. Riethman

School of Medical Diagnostics & Translational Sciences Publications

Large terminal fragments of human chromosomes 2p, 6q, 8q, 12q, and 18q were cloned using yeast artificial chromosomes (YACs). RecA-assisted restriction endonuclease (RARE) cleavage analysis of genomic DNA samples from 11 unrelated individuals using YAC-derived probes confirmed the telomeric localizations of the half-YACs studied. The cloned Fragments provide telomeric closure of maps for the respective chromosome arms and will supply the reagents needed for analyzing and sequencing these distal subtelomeric regions.

Cloning Of Multiple Novel Human Trinucleotide Repeat Containing Cdna's: A Novel Application Of Rapid Amplification Of Cdna Ends (Race), James P. Carney

Dissertations

No abstract provided.

Analysis Of Amino Acids Relevant To Activity And Substrate Specificity Of The Human Dna Repair Protein 0-6-Methylguanine Dna Methyltransferase (Mgmt), Susan Elizabeth Morgan

Dissertations

No abstract provided.

The Effects Of Ethanol On Growth Hormone And Prolactin Gene Expression In Male Rats, John James Tentler

Dissertations

No abstract provided.

Perinatal Regulation Of A Novel Mouse Cytochrome P450 Induced By Pregnancy, Helen Lietz

Dissertations

No abstract provided.

Proteolytic Processing Of The Murine Coronavirus Polymerase Polyprotein, Shanghong Dong

Dissertations

No abstract provided.

The Effects Of Ethanol On The Developing Serotonergic Neurons, Jung-Ae Kim

Dissertations

No abstract provided.

Formation Of The Isocyclic Ring Of Chlorophyll By Isolated Clamydomonas Reinhardtii Chloroplasts, David Bollivar

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.

Elimination Of Dissolved Sulfide Interference In The Flow-Injection Determination Of Sigma-Co2 By Addition Of Molybdate, Rigel L. Lustwerk, David J. Burdige

OES Faculty Publications

A previously described flow injection method for the analysis of ΣCO₂ included the addition of ZnCl₂ to some samples before analysis in order to precipitate dissolved sulfide (which interferes with the method) as ZnS. However, the use of Zn²⁺ in samples with high concentrations of dissolved sulfide causes the coprecipitation of ZnCO₃, and in our experience with this technique, ZnCO₃ also precipitates even in the absence of dissolved sulfide. The addition of molybdate effectively complexes dissolved sulfide without interfering with the determination of ΣCO2 by this technique.

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Factors Influencing The Oxidation Of Lipoproteins And Plasma Lipids, Yanshan Ma

Electronic Theses and Dissertations

The hypothesis that antioxidant vitamins (ascorbate and tocopherols) along with urate protect blood plasma lipids from oxidation was tested. Dietary fat is also an important factor influencing plasma lipid peroxidation. The purpose of this study was to investigate the role of plasma antioxidants and dietary fat on low density lipoprotein (LDL) and plasma lipid oxidation. In the first part of this study, we compared the ability of urate and ascorbate to protect human LDL from in vitro oxidation. LDL oxidation was initiated by 15 mM of a water soluble azo-initiator in the presence or absence of ascorbate or urate. The …

Semiclassical Quantization Of A Nonintegrable System: Pushing The Fourier Method Into The Chaotic Regime, Karl Sohlberg, Randall B. Shirts

Faculty Publications

Semiclassical Einstein–Brillouin–Keller (EBK) quantization of the nonintegrable Hénon–Heiles Hamiltonian succeeds using the Fourier transform method of Martens and Ezra. Two innovations are required for this success: (1) the use of tunneling corrected quantizing actions obtained from an approximate, one-dimensional Hamiltonian and (2) exploitation of intermediate-time approximate quasiperiodicity or "vague tori'' wherein the Fourier transform of chaotic motion over 10–100 vibrational periods allows the determination of frequencies and amplitudes which approximate motion during the time interval. Approximate tori, actions, and EBK energy levels are then straightforward. We use an interpolation method to smooth over small resonance zones that are not expected …

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 …

Lag-2 May Encode A Signaling Ligand For The Glp-1 And Lin-12 Receptors Of C-Elegans, Samuel T. Henderson, Dali Gao, Eric J. Lambie, Judith Kimble

Dartmouth Scholarship

The C. elegans lag-2 gene is required for several cell-cell interactions that rely on the receptors GLP-1 and LIN-12. In this paper, we report that lag-2 encodes a putative membrane protein with sequence similarity to Drosophila Delta, a proposed ligand for the Notch receptor. Furthermore, we show that the lag-2 promoter drives expression of a reporter protein in the signaling distal tip cell (DTC) of the DTC/germline interaction. By in situ hybridization, we have found that endogenous lag-2 mRNA is present in the DTC but not the germ line. One fusion protein, called LAG-2::beta-gal(intra), rescues a lag-2 null mutant and …

The Pha-4 Gene Is Required To Generate The Pharyngeal Primordium Of Caenorhabditis-Elegans, Susan E. Mango, Eric J. Lambie, Judith Kimble

Dartmouth Scholarship

In the 4-cell Caenorhabditis elegans embryo, two blastomeres are destined to generate pharyngeal cells, each by a distinct developmental strategy: one pathway is inductive, while the other is autonomous. Here, we identify the pha-4 locus. In animals lacking pha-4 activity, an early step in pharyngeal organogenesis is blocked: no pharyngeal primordium is formed and differentiated pharyngeal cells are absent. Most other tissues are generated normally in pha-4 mutants, including cells related to pharyngeal cells by cell lineage and position. Thus, pha-4 activity is required to form the pharyngeal primordium. We propose that pha-4 marks a convergence of the inductive and …

In Situ Regulation Of Cytosolic Phospolipase A₂, Beverly A. Rzigalinski

Theses and Dissertations in Biomedical Sciences

The 85 kDa cytosolic phospholipase A₂ (cPLA₂) is an agonist-responsive effector for intracellular signal transduction through the arachidonate cascade. In vitro studies have demonstrated that this enzyme is regulated by sub-micromolar calcium and is specific for arachidonate as the sn-2 fatty acyl group of phospholipid substrates. However, very little data is available regarding in situ mechanisms which govern the activity of cPLA₂. The primarily objective of these studies was to develop an in situ system for the study of cPLA₂, and investigate mobilization of arachidonate during signal transduction events.

Dimethylsulfoxide differentiation of the …

Role Of Heat Shock Protein 70 Kda Cognate In Limiting Thermal Inactivation And Refolding Of Heat-Denatured Nuclear Type I Topoisomerase, Kuo-Kuang Wen

Theses and Dissertations in Biomedical Sciences

Previous studies (Ciavarra et al., 1994) demonstrated that the constitutive 70 kDa heat shock protein (hsc70) protected purified topoisomerase I from thermal injury. In addition, hsc70 was capable of regenerating catalytic activity of heat-denatured topoisomerase I. A whole cell lysate was also active in this reaction assay. The present study demonstrates that heat-denatured topoisomerase I is reactivated by a cytosolic fraction and that this activity is dependent on the presence of cytosolic hsc70. The efficacy of hsc70-mediated refolding of heat-denatured topoisomerase I is greatly enhanced by a cytosolic cofactor(s). In all these refolding reactions, exogenous ATP is not required. Size …

Sensitivity Of Second Harmonic Generation To Space Charge Effects At Si(111)/Electrolyte And Si(111)/Sio2/Electrolyte Interfaces, P. R. Fischer, J. L. Daschbach, D. E. Gragson, G. L. Richmond

Chemistry and Biochemistry

The potential dependence in the surface second harmonic response from hydrogen terminated n‐Si(111) and oxidized n‐Si(111) surfaces has been examined in aqueous NH₄F and H₂SO₄ solutions. The relative phase of the nonlinear response as measured by rotational anisotropy experiments is found to be highly sensitive to the presence of the oxide and the field applied across the Si(111)/oxide/electrolyte interface. These observations are attributed to field effects within the space–charge region of the semiconductor which vary with the presence and thickness of the insulating oxide layer on the Si(111) surface.

Use Of An Oriented Transmembrane Protein To Probe The Assembly Of A Supported Phospholipid Bilayer, Paul Brian Contino, Carol A. Hasselbacher, J. B. Alexander Ross, Yale Nemerson

Chemistry and Biochemistry Faculty Publications

Planar-supported phopholipid bilayers formed by te adsorpton of vesicles are increasingly used in the investigation of lipK-ependent reactis. We have studied the way in which these bilayers are forned with phopholipid vesicles coaining the btranembrane protein Tssue Factor (TF). TF complexed with te senne protease, factor Vlla, is the primary initiator of bklod coagulation by way of activation of the zymogen factor X. TF has been shown to orient randomly on the inner and outer leaflets of vesicles. We used proteolytic digestion to produce vesicles in which the exracellular domain of TF is located on the inner leaflet These vesicles …

Heterologous Expression Of The Bchm Gene Product From Rhodobacter Capsulatus And Demonstration That It Encodes S-Adenosyl-L-Methionine: Mg-Protoporhyrin Ix Methyltransferase, David Bollivar

Scholarship

No abstract provided.

The Structure And Dynamics Of The Cs2 Molecular Ion, Karl Sohlberg, Chan Yibai

Faculty Publications

Several common elementary methods of computing molecular properties, prerequisite to molecular dynamics studies, are tested for their validity for CS+2. Judged sufficiently accurate, these methods are then used to aid in investigating the collisionally activated dissociation of CS+2 upon impact with xenon. Rice–Ramsperger–Kassel–Marcus (RRKM) unimolecular decay rate calculations are presented and compared to experimental studies employing collisional activation. RRKM theory is shown to reproduce the experimental results for collision energies near threshold. When corrected for vibrational anharmonicity, the RRKM calculation shows agreement with the experimental results over a slightly wider range of energies. A discussion is given on the applicability …

Crystallization Of Hemoglobins Ii And Iii Of The Symbiont-Harboring Clam Lucina Pectinata, M. A. Doyle, Jacqueline Vitali, J. B. Wittenberg, S. N. Vinogradov, D. A. Walz, B. F.P. Edwards, P. D. Martin

Physics Faculty Publications

Diffraction data to 2.7 A resolution were measured on crystals of the homotetramers of components II and III of the cytoplacmic hemoglobin of the symbiont-harboring clam Lucina pectinata. Even though the crystallization conditions are different and the sequence homology of the two hemoglobins is only 63%, the crystals are isomorphous to each other and to the heterotetramer Hb II/III, implying that the residues primarily involved in the intermolecular interactions and responsible for crystal cohesion may be invariant.

Dissection Of An Antibody-Catalyzed Reaction, Jon D. Stewart, Joseph F. Krebs, Gary Siuzdak, Anthony J. Berdis, David B. Smithrud, Stephen J. Benkovic

Chemistry Faculty Publications

Antibody 43C9 accelerates the hydrolysis of a p-nitroanilide by a factor of 2.5 x 10(5) over the background rate in addition to catalyzing the hydrolysis of a series of aromatic esters. Since this represents one of the largest rate accelerations achieved with an antibody, we have undertaken a series of studies aimed at uncovering the catalytic mechanism of 43C9. The immunogen, a phosphonamidate, was designed to mimic the geometric and electronic characteristics of the tetrahedral intermediate that forms upon nucleophilic attack by hydroxide on the amide substrate. Further studies, however, revealed that the catalytic mechanism is more complex and involves …

Circadian Clock Locus Frequency: Protein Encoded By A Single Open Reading Frame Defines Period Length And Temperature Compensation., Benjamin D. Aronson, Keith A. Johnson, Jay C. Dunlap

Dartmouth Scholarship

The frequency (frq) locus encodes a key component, a state variable, in a cellular oscillator generating circadian rhythmicity. Two transcripts have been mapped to this region, and data presented here are consistent with the existence of a third transcript. Analysis of cDNA clones and clock mutants from this region focuses attention on one transcript encoding a protein. FRQ, which is a central clock component: (i) mutations in all of the semidominant frq alleles are the result of single amino acid substitutions and map to the open reading frame (ORF) encoding FRQ; (ii) deletion of this ORF, or a frameshift mutation …

Cystic Fibrosis Transmembrane Conductance Regulator Mutations That Disrupt Nucleotide Binding, James Logan, David Hiestand, Paru Daram, Zhen Huang, Donald D. Muccio, John Hartman, Boyd Haley, William J. Cook, Eric J. Sorscher

Molecular and Cellular Biochemistry Faculty Publications

Increasing evidence suggests heterogeneity in the molecular pathogenesis of cystic fibrosis (CF). Mutations such as deletion of phenylalanine at position 508 (delta F508) within the cystic fibrosis transmembrane conductance regulator (CFTR), for example, appear to cause disease by abrogating normal biosynthetic processing, a mechanism which results in retention and degradation of the mutant protein within the endoplasmic reticulum. Other mutations, such as the relatively common glycine-->aspartic acid replacement at CFTR position 551 (G551D) appear to be normally processed, and therefore must cause disease through some other mechanism. Because delta F508 and G551D both occur within a predicted nucleotide binding …

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 …