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2000

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Articles 391 - 420 of 2418

Full-Text Articles in Life Sciences

The Affect Of Low Intensity, Progressive, Aerobic Exercise Training On Cardiovascular Function In The Diabetic Rat, Steven Michael Bauer Aug 2000

The Affect Of Low Intensity, Progressive, Aerobic Exercise Training On Cardiovascular Function In The Diabetic Rat, Steven Michael Bauer

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Masters of Science in Biology by Steven Michael Bauer on August 4, 2000.


Verbena Urticifolia L., Jennifer A. Ward Aug 2000

Verbena Urticifolia L., Jennifer A. Ward

Specimens by Name

No abstract provided.


Fipronil Metabolism, Oxidative Sulfone Formation And Toxicity Among Organophosphate- And Carbamate-Resistant And Susceptible Western Corn Rootworm Populations , Michael E. Scharf, Blair D. Siegfried, Lance J. Meinke, Laurence D. Chandler Aug 2000

Fipronil Metabolism, Oxidative Sulfone Formation And Toxicity Among Organophosphate- And Carbamate-Resistant And Susceptible Western Corn Rootworm Populations , Michael E. Scharf, Blair D. Siegfried, Lance J. Meinke, Laurence D. Chandler

Department of Entomology: Faculty Publications

Fipronil toxicity and metabolism were studied in two insecticide-resistant, and one susceptible western corn rootworm (Diabrotica virgifera virgifera, LeConte) populations. Toxicity was evaluated by exposure to surface residues and by topical application. Surface residue bioassays indicated no differences in fipronil susceptibility among the three populations. Topical bioassays were used to study the relative toxicity of fipronil, fipronil. the mono-oxygenase inhibitor piperonyl butoxide, and fipronil's oxidative sulfone metabolite in two populations (one resistant with elevated mono-oxygenase activity). Fipronil and fipronil-sulfone exhibited similar toxicity and application of piperonyl butoxide prior to fipronil resulted in marginal effects on toxicity. Metabolism of …


Acer Nigrum Michx.F., John E. Ebinger Aug 2000

Acer Nigrum Michx.F., John E. Ebinger

Specimens by Name

No abstract provided.


Direct Farm Marketing - Rural Economic Development Opportunities, Marilyn R. Schlake Aug 2000

Direct Farm Marketing - Rural Economic Development Opportunities, Marilyn R. Schlake

Cornhusker Economics

Direct farm marketing is once again on the rise. Enterprising producers across the nation are developing a renewed interest in direct sales for numerous reasons - - low farm-gate prices, increased interaction between farming communities and growing suburbs, increased interest in food safety and the environment and a willingness of consumers to purchase food products at a premium price. Direct marketing potentially means preserving small farms, strengthening the social relations between rural and urban citizens and rural economic development.


Palatability Of Beef Steaks Marinated With Solutions Of Calcium Chloride, Phosphate, And (Or) Beef-Flavoring, J. A. Scanga, R. J. Delmore Jr., R. P. Ames, K. E. Belk, J. D. Tatum, G. C. Smith Aug 2000

Palatability Of Beef Steaks Marinated With Solutions Of Calcium Chloride, Phosphate, And (Or) Beef-Flavoring, J. A. Scanga, R. J. Delmore Jr., R. P. Ames, K. E. Belk, J. D. Tatum, G. C. Smith

Animal Science

This study evaluated the efficacy of marination for increasing consumer acceptability of beef. Top-sirloin steaks from 28 USDA select steers were randomly assigned to one of six marination treatments: control (CT), 150 mM calcium chloride (CA), 10% solution of beef-flavoring/seasoning mixture (FL), CA and FL (CF), 2.5% sodium phosphate and FL (PF), and tap water (TW). Steaks were marinated in vacuum pouches, aged for 7 days, cooked to 70°C and evaluated by a trained sensory panel. Marination with CA did not affect tenderness ratings, but increased (P


Legume Logic Number 120 Aug 2000

Legume Logic Number 120

Legume Logic

Contents

Lupin/Legume Logic turns Ten

Beethoven not good enough!

Southern Pulse group

Belara and Aphids

Pulse points

Lupin pools


Kentucky Warbler (Vol. 76, No. 3), Kentucky Library Research Collections Aug 2000

Kentucky Warbler (Vol. 76, No. 3), Kentucky Library Research Collections

The Kentucky Warbler

No abstract provided.


Effect Of The Direction Of The Blast On Vegetation Recovery Within The Zone Of Devastation Created By The May 18, 1980 Eruption Of Mount St. Helens, Washington, Dmitri Barkovsky Aug 2000

Effect Of The Direction Of The Blast On Vegetation Recovery Within The Zone Of Devastation Created By The May 18, 1980 Eruption Of Mount St. Helens, Washington, Dmitri Barkovsky

All-Inclusive List of Electronic Theses and Dissertations

A number of different remote sensing techniques were used to analyze Landsat TM image data in order to study vegetation recovery patterns at three locations within the zone of devastation of Mount St. Helens (MSH). Prior to the May 18, 1980 eruption, the vegetation in the area ofMSH was characterized by mature coniferous forest disturbed only by a few clearcuts, according to analysis of Landsat MSS data. As a result of the MSH eruption, more than 600 sq. km of the area predominantly north of the volcano were severely devastated by a number of volcanic events such as phreatic explosions, …


Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, Kenneth I. Strauss, Mary F. Barbe, Renee Marshall Demarest, Ramesh Raghupathi, Samir Mehta, Raj K. Narayan Aug 2000

Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, Kenneth I. Strauss, Mary F. Barbe, Renee Marshall Demarest, Ramesh Raghupathi, Samir Mehta, Raj K. Narayan

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Cyclooxygenase-2 (COX2) is a primary inflammatory mediator that converts arachidonic acid into precursors of vasoactive prostaglandins, producing reactive oxygen species in the process. Under normal conditions COX2 is not detectable, except at low abundance in the brain. This study demonstrates a distinctive pattern of COX2 increases in the brain over time following traumatic brain injury (TBI). Quantitative lysate ribonuclease protection assays indicate acute and sustained increases in COX2 mRNA in two rat models of TBI. In the lateral fluid percussion model, COX2 mRNA is significantly elevated (>twofold, p < 0.05, Dunnett) at 1 day postinjury in the injured cortex and bilaterally in the hippocampus, compared to sham-injured controls. In the lateral cortical impact model (LCI), COX2 mRNA peaks around 6 h postinjury in the ipsilateral cerebral cortex (fivefold induction, p < 0.05, Dunnett) and in the ipsilateral and contralateral hippocampus (two- and six-fold induction, respectively, p < 0.05, Dunnett). Increases are sustained out to 3 days postinjury in the injured cortex in both models. Further analyses use the LCI model to evaluate COX2 induction. Immunoblot analyses confirm increased levels of COX2 protein in the cortex and hippocampus. Profound increases in COX2 protein are observed in the cortex at 1-3 days, that return to sham levels by 7 days postinjury (p < 0.05, Dunnett). The cellular pattern of COX2 induction following TBI has been characterized using immunohistochemistry. COX2-immunoreactivity (-ir) rises acutely (cell numbers and intensity) and remains elevated for several days following TBI. Increases in COX2-ir colocalize with neurons (MAP2-ir) and glia (GFAP-ir). Increases in COX2-ir are observed in cerebral cortex and hippocampus, ipsilateral and contralateral to injury as early as 2 h postinjury. Neurons in the ipsilateral parietal, perirhinal and piriform cortex become intensely COX2-ir from 2 h to at least 3 days postinjury. In agreement with the mRNA and immunoblot results, COX2-ir appears greatest in the contralateral hippocampus. Hippocampal COX2-ir progresses from the pyramidal cell layer of the CA1 and CA2 region at 2 h, to the CA3 pyramidal cells and dentate polymorphic and granule cell layers by 24 h postinjury. These increases are distinct from those observed following inflammatory challenge, and correspond to brain areas previously identified with the neurological and cognitive deficits associated with TBI. While COX2 induction following TBI may result in selective beneficial responses, chronic COX2 production may contribute to free radical mediated cellular damage, vascular dysfunction, and alterations in cellular metabolism. These may cause secondary injuries to the brain that promote neuropathology and worsen behavioral outcome.


Morphological, Molecular, And Biogeographical Variation Within The Imperiled Virginia Spiraea, Constance Anders Aug 2000

Morphological, Molecular, And Biogeographical Variation Within The Imperiled Virginia Spiraea, Constance Anders

Masters Theses & Specialist Projects

Spiraea virginiana Britton is a rare federally listed rhizomatous shrub endemic to the southern Blue Ridge and Appalachian Plateau physiographic provinces. Populations of S. virginiana are found restricted to scoured sections of high gradient streams within the Ohio River drainage. Present evidence indicates the species is reproducing asexually, most probably through the deposition of rhizomes from upstream populations forming new downstream ramets. Phenotypic variation was examined through a morphometric evaluation of 25 leaf measurements and analyzed using Principal Components Analysis (PCA) and discriminant function analysis. Identity and structure at the molecular level as examined with Randomly Amplified Polymorphic DNA (RAPDs) …


Ard News August 2000 Aug 2000

Ard News August 2000

Agricultural Research Division: News and Annual Reports

CONTENTS:

Comments from the Dean
ARD Advisory Council Annual Report to Faculty
Natural Resouurces and Research Update
ARD Advisory Council Election Results
Anna Elliott Proposals
Sampson Range and Pasture Management Endowments
Sampson Range and Pasture Management Endowments
Widaman Trust Distinguished Graduate Assistant Award
Hardin Distinguished Graduate Fellowship for 2000-2001
National Research Initiative Report for 1999
Shear-Miles Fellowship 2000-2001
NRC Assessment of the National Research Initiative
USDA - ARS Research Leader Dr. Philip J. Schall
USDA Science and Education Impact Sheets
Congratulations to Faculty - Successful USDA Grant Proposals
Proposals Submitted for Federal Grants
New or Revised Projects
Grants and Contracts …


The International Lepidoptera Survey Newsletter, August 2000, International Lepidoptera Survey, Ron Gatrelle Aug 2000

The International Lepidoptera Survey Newsletter, August 2000, International Lepidoptera Survey, Ron Gatrelle

International Lepidoptera Survey Newsletter

Contents

Brephidium isophthalma insularus

Lepidopterists’ Society Annual Meeting

Phenosyncronic subspeciation

Announcement: Be watching for The International Lepidoptera Survey interactive web site

A Day of Collecting in Burke County Georgia by Ron Gatrelle (pages 3-5)


Nebline, August 2000 Aug 2000

Nebline, August 2000

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Handling Food Safely at Home
Controlling Undesirable Perennial Grasses in the Lawn
Purple Loosestrife Noxious Weed
Storing Extra Seeds
Your Hummingbird Feeders Should Be Up and Running
Tips for Non-toxic Cricket and Spider Control
West Nile Virus and Rabbit Calcivirus Disease Alerts
New Website Help for Wildlife Damage Problems
Be Wary of Nitrate, Prussic Acid Poisoning This Summer
Deadline Approaches to Terminate Farm Leases
Fuel Price Adds $10 Per Acre to Irrigation Cost
Protect Hearing on the Farm
The Financial Plan
Marketing Strategies
Avoid Foliar Diseases on Tomatoes
Blight Affects Junipers, Windbreaks
Drinking Water Questions and Answers
200 Youth Explore …


Swapping Space For Time And Unfair Tests Of Ecological Models, Andrew J. Tyre, Brigitte Tenhumberg, Michael A. Mccarthy, Hugh P. Possingham Aug 2000

Swapping Space For Time And Unfair Tests Of Ecological Models, Andrew J. Tyre, Brigitte Tenhumberg, Michael A. Mccarthy, Hugh P. Possingham

School of Biological Sciences: Faculty Publications

Testing ecological models for management is an increasingly important part of the maturation of ecology as an applied science. Consequently, we need to work at applying fair tests of models with adequate data. We demonstrate that a recent test of a discrete time, stochastic model was biased towards falsifying the predictions. If the model was a perfect description of reality, the test falsified the predictions 84% of the time. We introduce an alternative testing procedure for stochastic models, and show that it falsifies the predictions only 5% of the time when the model is a perfect description of reality. The …


Hidden Mechanisms Generate Negative Feedbacks In A Stochastic Model: A Comment On Murray, Andrew J. Tyre, Brigitte Tenhumberg Aug 2000

Hidden Mechanisms Generate Negative Feedbacks In A Stochastic Model: A Comment On Murray, Andrew J. Tyre, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

The debate between density-dependent and densityindependent population regulation is one of the oldest and most vociferous in ecology. Australian ecologists participated from the beginning (Nicholson 1933; Andrewartha & Birch 1954). Despite recent efforts to put the debate to rest (Turchin 1995, 1999), there appears little likelihood of either side abandoning the ramparts (Bonsall et al. 1998). Murray (2000; this issue) uses a stochastic simulation model to argue that a significant statistical relationship between birth rate and population size (i.e. density dependence) can arise in the absence of negative feedbacks of population size on fecundity. In this comment we demonstrate that …


Nutrient Absorption And Utilization By Wing And Flight Muscle Morphs Of The Cricket Gryllus Firmus: Implications For The Trade-Off Between Flight Capability And Early Reproduction, Anthony J. Zera, Tammy Brink Aug 2000

Nutrient Absorption And Utilization By Wing And Flight Muscle Morphs Of The Cricket Gryllus Firmus: Implications For The Trade-Off Between Flight Capability And Early Reproduction, Anthony J. Zera, Tammy Brink

Anthony Zera Publications

Absorption efficiency (AD, approximate digestibility, assimilation efficiency) of various macronutrients and conversion of absorbed nutrients to biomass (ECD) were compared among the two types of flightless morph and the flight-capable morph of the cricket, Gryllus firmus. No biologically significant phenotypic or genetic difference in AD for carbohydrate, protein or lipid was observed among morphs fed either a high-nutrient (100%) or a low-nutrient (25%) diet. Thus, previously-documented differences among adult morphs in carbohydrate and lipid content must be caused by processes other than variation in nutrient absorption by morphs during adulthood. Relative absorption efficiency of total dry mass of food …


Hexapod Herald - Vol. 12, No. 3, August 2000 Aug 2000

Hexapod Herald - Vol. 12, No. 3, August 2000

Hexapod Herald and Other Entomology Department Newsletters

Calendar of events

Grants

Welcome

Faculty news

Graduate student news

Publications

Travel

From the office


Forage News [2000-08], Department Of Plant And Soil Sciences, University Of Kentucky Aug 2000

Forage News [2000-08], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

  • Southern Beef Day Set for October 6 in Somerset
  • Late Summer Forage Establishment
  • Hay Contest Can Mean Big Bucks at Southern Beef Day
  • AFGC Conference
  • Extending Pasture Through Stockpiling
  • Upcoming Events


North Atlantic Intermediate To Deep Water Circulation And Chemical Stratification During The Past 1 Myr, Benjamin P. Flower, D. W. Oppo, J. F. Mcmanus, K. A. Venz, D. A. Hodell, J. L. Cullen Aug 2000

North Atlantic Intermediate To Deep Water Circulation And Chemical Stratification During The Past 1 Myr, Benjamin P. Flower, D. W. Oppo, J. F. Mcmanus, K. A. Venz, D. A. Hodell, J. L. Cullen

Marine Science Faculty Publications

Benthic foraminiferal carbon isotope records from a suite of drill sites in the North Atlantic are used to trace variations in the relative strengths of Lower North Atlantic Deep Water (LNADW), Upper North Atlantic Deep Water (UNADW), and Southern Ocean Water (SOW) over the past 1 Myr. During glacial intervals, significant increases in intermediate-to-deep delta(13)C gradients (commonly reaching >1.2 parts per thousand) are consistent with changes in deep water circulation and associated chemical stratification. Bathymetric delta(13)C gradients covary with benthic foraminiferal delta(18)O and covary inversely with Vostok CO2, in agreement with chemical stratification as a driver of atmospheric CO2 changes. …


Growing Lavender In Western Australia, Aileen Reid Aug 2000

Growing Lavender In Western Australia, Aileen Reid

Bulletins 4000 -

Lavender oil is an essential oil, derived from plants (genus Lavendulai primarily by steam distillation of the flowers. There are several types of lavender oil. The 'true' lavender oil, and the most highly prized, comes from Lavendula augustifolia; it is primarily used in the fragrance and perfume industry. World production is about 200 tonnes per year. Spike lavender oil, derived from Lavendula latifolia, has a world production of about 150-200 tonnes per year. Lavandin oil is derived from hybrids of L. augustifolia x L. latifolia that yield much higher than L. augustifolia but the oil is lower quality, hence it …


Regional Variation In Recruitment Of Hemlock Seedlings And Saplings In The Upper Great Lakes, Usa, Thomas P. Rooney, Ronald J. Mccormick, Stephen L. Solheim, Donald M. Waller Aug 2000

Regional Variation In Recruitment Of Hemlock Seedlings And Saplings In The Upper Great Lakes, Usa, Thomas P. Rooney, Ronald J. Mccormick, Stephen L. Solheim, Donald M. Waller

Biological Sciences Faculty Publications

Mature eastern hemlock–northern hardwood forest cover decreased drastically in the upper Midwest following European settlement and has yet to rebound substantially. Previous studies show that stands retaining substantial hemlock canopy coverage have low hemlock seedling and sapling densities. Results from various geographically restricted studies suggest several possible mechanisms that could cause low seedling or sapling density. We examined the relative importance of these proposed mechanisms in the Southern Superior Uplands Section of the Laurentian Forest Province. We surveyed 294- m2 plots in 100 hemlock stands in northern Wisconsin and western upper Michigan to assess how these proposed mechanisms affect the …


Sequences Of Citrus Tristeza Virus Separated In Time And Space Are Essentially Identical, Maria R. Albiach-Marti, Munir Mawassi, Siddarame Gowda, Satyanarayana Tatineni, Mark E. Hilf, Savita Shanker, Ernesto C. Almira, Maria C. Vives, Carmelo Lopez, Jose Guerri, Ricardo Flores, Pedro Moreno, Steve M. Garnsey, William O. Dawson Aug 2000

Sequences Of Citrus Tristeza Virus Separated In Time And Space Are Essentially Identical, Maria R. Albiach-Marti, Munir Mawassi, Siddarame Gowda, Satyanarayana Tatineni, Mark E. Hilf, Savita Shanker, Ernesto C. Almira, Maria C. Vives, Carmelo Lopez, Jose Guerri, Ricardo Flores, Pedro Moreno, Steve M. Garnsey, William O. Dawson

Department of Plant Pathology: Faculty Publications

The first Citrus tristeza virus (CTV) genomes completely sequenced (19.3-kb positive-sense RNA), from four biologically distinct isolates, are unexpectedly divergent in nucleotide sequence (up to 60% divergence). Understanding of whether these large sequence differences resulted from recent evolution is important for the design of disease management strategies, particularly the use of genetically engineered mild (essentially symptomless)-strain cross protection and RNA-mediated transgenic resistance. The complete sequence of a mild isolate (T30) which has been endemic in Florida for about a century was found to be nearly identical to the genomic sequence of a mild isolate (T385) from Spain. Moreover, samples of …


Pseudomonas Syringae Hrp Type Iii Secretion System And Effector Proteins, Alan Collmer, Jorge L. Badel, Amy O. Charkowski, Wen-Ling Deng, Derrick E. Fouts, Adela R. Ramos, Amos H. Rehm, Deborah M. Anderson, Olaf Schneewind, Karin V. Van Dijk, James R. Alfano Aug 2000

Pseudomonas Syringae Hrp Type Iii Secretion System And Effector Proteins, Alan Collmer, Jorge L. Badel, Amy O. Charkowski, Wen-Ling Deng, Derrick E. Fouts, Adela R. Ramos, Amos H. Rehm, Deborah M. Anderson, Olaf Schneewind, Karin V. Van Dijk, James R. Alfano

Center for Plant Science Innovation: Faculty Publications

Pseudomonas syringae is a member of an important group of Gram-negative bacterial pathogens of plants and animals that depend on a type III secretion system to inject virulence effector proteins into host cells. In P. syringae, hrpyhrc genes encode the Hrp (type III secretion) system, and avirulence (avr) and Hrpdependent outer protein (hop) genes encode effector proteins. The hrpyhrc genes of P. syringae pv syringae 61, P. syringae pv syringae B728a, and P. syringae pv tomato DC3000 are flanked by an exchangeable effector locus and …


Chromatin Organization And Transcriptional Control Of Gene Expression In Drosophila, G Farkas, B Leibovitch, Sarah C.R. Elgin Aug 2000

Chromatin Organization And Transcriptional Control Of Gene Expression In Drosophila, G Farkas, B Leibovitch, Sarah C.R. Elgin

Biology Faculty Research

It is increasingly clear that the packaging of DNA in nucleosome arrays serves not only to constrain the genome within the nucleus, but also to encode information concerning the activity state of the gene. Packaging limits the accessibility of many regulatory DNA sequence elements and is functionally significant in the control of transcription, replication, repair and recombination. Here, we review studies of the heat-shock genes, illustrating the formation of a specific nucleosome array at an activatable promoter, and describe present information on the roles of DNA-binding factors and energy-dependent chromatin remodeling machines in facilitating assembly of an appropriate structure. Epigenetic …


Uncharged Trna Activates Gcn2 By Displacing The Protein Kinase Moiety From A Bipartite Trna-Binding Domain, Jinsheng Dong, Hongfang Qiu, Minerva Garcia-Barrio, James T. Anderson, Alan G. Hinnebusch Aug 2000

Uncharged Trna Activates Gcn2 By Displacing The Protein Kinase Moiety From A Bipartite Trna-Binding Domain, Jinsheng Dong, Hongfang Qiu, Minerva Garcia-Barrio, James T. Anderson, Alan G. Hinnebusch

Biological Sciences Faculty Research and Publications

Protein kinase GCN2 regulates translation in amino acid–starved cells by phosphorylating eIF2. GCN2 contains a regulatory domain related to histidyl-tRNA synthetase (HisRS) postulated to bind multiple deacylated tRNAs as a general sensor of starvation. In accordance with this model, GCN2 bound several deacylated tRNAs with similar affinities, and aminoacylation of tRNAPhe weakened its interaction with GCN2. Unexpectedly, the C-terminal ribosome binding segment of GCN2 (C-term) was required in addition to the HisRS domain for strong tRNA binding. A combined HisRS+C-term segment bound to the isolated protein kinase (PK) domain in vitro, and tRNA impeded this interaction. An activating mutation …


Development Of A Photoinitiator Blend For Uv Cured Inks And Coatings, Madhu Bansal Aug 2000

Development Of A Photoinitiator Blend For Uv Cured Inks And Coatings, Madhu Bansal

Masters Theses

The purpose of this study is to develop a new standard blend of photoinitiators, having properties of low odor, high solubility, faster curing, and being efficient for pigmented as well as for clear systems. In the process, we expect to understand the behavior of mixtures of photoinitiators and their resulting UV spectra. An important first step is to prepare different blend with different photoinitiator and characterize them on cure basis. Curing properties were studied by the KMnO4 yellow stain density test. The absorption range in the UV spectra was measured for each Photoinitiator with methanol and acrylate as background …


The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon Aug 2000

The Influence Of The Pressure Head On The Indonesian Seas Circulation, William H. Burnett, Vladimir M. Kamenkovich, George L. Mellor, Arnold L. Gordon

Faculty Publications

A high resolution, regional, non-linear, barotropic ocean model (2D POM) was used to show that a pressure difference between the Pacific and Indian Ocean does not significantly influence the total transport of the Indonesian throughflow.


B.R. Wells Rice Research Studies 1999, R. J. Norman, C. A. Beyrouty Aug 2000

B.R. Wells Rice Research Studies 1999, R. J. Norman, C. A. Beyrouty

Arkansas Agricultural Experiment Station Research Series

No abstract provided.


Crystallization And Structure Determination Of The Catalytic Trimer Of Methanococcus Jannaschii Aspartate Transcarbamoylase, Jacqueline Vitali, Tatyana Vorobyova, Gordon Websterb, Evan R. Kantrowitza Aug 2000

Crystallization And Structure Determination Of The Catalytic Trimer Of Methanococcus Jannaschii Aspartate Transcarbamoylase, Jacqueline Vitali, Tatyana Vorobyova, Gordon Websterb, Evan R. Kantrowitza

Physics Faculty Publications

Aspartate transcarbamoylase (ATCase) catalyzes the first step in the pyrimidine biosynthetic pathway, the reaction between carbamoyl phosphate and L-aspartate to form N-carbamoyl-L-aspartate and phosphate. The structural analysis of the ATCase catalytic trimer from Methanococcus jannaschii, a unicellular thermophilic archaeabacterium, has been undertaken in order to gain insight into the structural features that are responsible for the thermostability of the enzyme. As a first step, the catalytic trimer was crystallized in space group R32, with unit-cell parameters a = b = 265.3, c = 195.5 Å and two trimers in the asymmetric unit. Its structure was determined using …